{"kind": "plan", "major": "18", "item": {"slug": "custom-scan", "name": "Custom Scan", "name_zh": "CustomScan", "category": "\u6269\u5c55\u673a\u5236", "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "aliases": ["Custom Scan (%s)", "CustomScan", "T_CustomScan"], "content_hash": "e48b8cdafc1aa48c1d5be9335a97f1f67cfac24f646def2bc45e2cfd6698abd1", "versions": {"10": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "8bff0b235093500fbdf848e29c05e40506abe5e45b5e924cfb11db936841829f", "archive_sha256": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=10", "label": "EXPLAIN"}, {"url": "/docs/10/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/10/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 10.23 source archive", "label": "10.23", "major": "10", "channel": "historical", "revision": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9", "source_url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "line": 1005, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1005", "sha256": "a785298532047cfeda969e78c3597a343dc1c56d61ba85830b0f16a02a14b5a1", "archive_sha256": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, {"url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "line": 282, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:282", "sha256": "cea76648bb38ae55f18f989768bee1a4ee025691ceea0f86bccb29dcdc166acc", "archive_sha256": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, {"url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "8bff0b235093500fbdf848e29c05e40506abe5e45b5e924cfb11db936841829f", "archive_sha256": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, {"url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "d562c321108844798cd234303fffb618f13d4ee3f3a5ac79bfd963b077e47c22", "archive_sha256": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/10/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "10", "build_id": 63, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "04aacb3e491b4aeabbfc54a60ddedcc5fafcc469c0823a375c35a83ec42575c6", "fragment_sha256": "82af09517c7be979ac518f6bede1cb5e44f328ebf207cc6b25aa2313dff5f7a6", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:62997ea80516ad012fbf6359de33f3b016b54c47e2df76e75606116b4baaf8e5", "translated_from_revision": null}, "body_sha256": "db725ece15085d3d9545569f598d74fb114dcb52bfb4464a312988c75cb9c7aa", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5\u5b58\u5728\u57fa\u7840\u5173\u7cfb\uff0c\u5219\u6253\u5f00\u5b83\u5e76\u83b7\u53d6\u9002\u5f53\u7684\u9501\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "10", "text_hash": "941afbb5600523c8f19d413bf61785aada3e5beaffa79ef2194a8cadd6681b6c", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/10/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "10", "build_id": 63, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "04aacb3e491b4aeabbfc54a60ddedcc5fafcc469c0823a375c35a83ec42575c6", "fragment_sha256": "82af09517c7be979ac518f6bede1cb5e44f328ebf207cc6b25aa2313dff5f7a6", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:62997ea80516ad012fbf6359de33f3b016b54c47e2df76e75606116b4baaf8e5", "translated_from_revision": null}, "body_sha256": "db725ece15085d3d9545569f598d74fb114dcb52bfb4464a312988c75cb9c7aa", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5\u5b58\u5728\u57fa\u7840\u5173\u7cfb\uff0c\u5219\u6253\u5f00\u5b83\u5e76\u83b7\u53d6\u9002\u5f53\u7684\u9501\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p> <span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/10/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/10/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "10", "link_map": {"/zh/docs/10/sql-explain.html": "/docs/10/sql-explain.html", "/zh/docs/10/performance-tips.html#USING-EXPLAIN": "/docs/10/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p> <span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/10/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/10/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "b097956e8266c75ef350ab6d9de17f6ac2eabf15316f0b9e4447b79d7b468b43", "content_hash": "941afbb5600523c8f19d413bf61785aada3e5beaffa79ef2194a8cadd6681b6c", "source_database": "center", "source_revision": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5\u5b58\u5728\u57fa\u7840\u5173\u7cfb\uff0c\u5219\u6253\u5f00\u5b83\u5e76\u83b7\u53d6\u9002\u5f53\u7684\u9501\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/10/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/10/facts/0/label": "Core node tag", "/versions/10/facts/1/label": "Structured EXPLAIN Node Type", "/versions/10/facts/2/label": "Inputs", "/versions/10/facts/2/value": "Provider-defined plan, possibly with children", "/versions/10/facts/3/label": "Output", "/versions/10/facts/3/value": "Provider-defined tuples", "/versions/10/facts/4/label": "Executor initializer", "/versions/10/facts/5/label": "Memory mechanism", "/versions/10/tables/0/title": "EXPLAIN labels in this source build", "/versions/10/related/1/label": "Using EXPLAIN", "/versions/10/related/2/label": "Parallel plans", "/versions/10/sections/0/title": "EXPLAIN names and attributes", "/versions/10/sections/1/title": "Memory and temporary storage", "/versions/10/sections/2/title": "Parallel execution and instrumentation", "/versions/10/sections/3/title": "Executor implementation notes", "/versions/10/sections/4/title": "EXPLAIN identity in core source", "/versions/10/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/10/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/10/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/10/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/10/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/10/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/10/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/10/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/10/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/10/sections/3/paragraphs/2": "open the base relation, if any, and acquire an appropriate lock on it", "/versions/10/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/10/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/10/tables/0/columns/0/label": "Text-format label", "/versions/10/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "3f66e39e60049bcec9e87d12595714d34a432edbb062ab5634a1aad1f60a51f5", "canonical_center_text_hash": "941afbb5600523c8f19d413bf61785aada3e5beaffa79ef2194a8cadd6681b6c"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p> <span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/10/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/10/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "11": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": 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[{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5\u5b58\u5728\u57fa\u7840\u5173\u7cfb\uff0c\u5219\u6253\u5f00\u5b83\u5e76\u83b7\u53d6\u9002\u5f53\u7684\u9501\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "11", "text_hash": "b9ebe8360ed11481598e9ebac59661dfc20a2564e46a76e95e9cb89a6c261370", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/11/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "11", "build_id": 64, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "617a30102327f61276ba77fb034f4bf1bbb677d91d4eb5507dc14d740e6394c9", "fragment_sha256": "a7b71780192bea8bfc169883aae459f6d32a71fe928f60388479827c9c8b54bc", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:ef5c7bc074acae9795db16e6b7482aea3b222bd4bcce0f76831332b97a21e8a1", "translated_from_revision": null}, "body_sha256": "1912b727350721f16ceee0a715c7f8a0dcba3b2d4f02423e1cdafa24d4aed137", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5\u5b58\u5728\u57fa\u7840\u5173\u7cfb\uff0c\u5219\u6253\u5f00\u5b83\u5e76\u83b7\u53d6\u9002\u5f53\u7684\u9501\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/11/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/11/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "11", "link_map": {"/zh/docs/11/sql-explain.html": "/docs/11/sql-explain.html", "/zh/docs/11/performance-tips.html#USING-EXPLAIN": "/docs/11/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/11/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/11/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "e3fa5ab75817daa7316a5344fc548b44e9185056b7526b3138d6b649f49df186", "content_hash": "b9ebe8360ed11481598e9ebac59661dfc20a2564e46a76e95e9cb89a6c261370", "source_database": "center", "source_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5\u5b58\u5728\u57fa\u7840\u5173\u7cfb\uff0c\u5219\u6253\u5f00\u5b83\u5e76\u83b7\u53d6\u9002\u5f53\u7684\u9501\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/11/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/11/facts/0/label": "Core node tag", "/versions/11/facts/1/label": "Structured EXPLAIN Node Type", "/versions/11/facts/2/label": "Inputs", "/versions/11/facts/2/value": "Provider-defined plan, possibly with children", "/versions/11/facts/3/label": "Output", "/versions/11/facts/3/value": "Provider-defined tuples", "/versions/11/facts/4/label": "Executor initializer", "/versions/11/facts/5/label": "Memory mechanism", "/versions/11/tables/0/title": "EXPLAIN labels in this source build", "/versions/11/related/1/label": "Using EXPLAIN", "/versions/11/related/2/label": "Parallel plans", "/versions/11/sections/0/title": "EXPLAIN names and attributes", "/versions/11/sections/1/title": "Memory and temporary storage", "/versions/11/sections/2/title": "Parallel execution and instrumentation", "/versions/11/sections/3/title": "Executor implementation notes", "/versions/11/sections/4/title": "EXPLAIN identity in core source", "/versions/11/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/11/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/11/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/11/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/11/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/11/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/11/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/11/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/11/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/11/sections/3/paragraphs/2": "open the base relation, if any, and acquire an appropriate lock on it", "/versions/11/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/11/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/11/tables/0/columns/0/label": "Text-format label", "/versions/11/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "5f6c32f47b787b34261911651947ea1c82c4cb4b07f589fdb02f211340cf575a", "canonical_center_text_hash": "b9ebe8360ed11481598e9ebac59661dfc20a2564e46a76e95e9cb89a6c261370"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/11/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> 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["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "12", "text_hash": "6c63531ff5e84c401044c504535f203b66543f4bb15eea92526894351d31c8b7", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/12/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "12", "build_id": 65, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "773efea8d76bcea57eb449ceb506a51025a4125ceaa9b765a1039e558f5cfe98", "fragment_sha256": "5563b70cc4f15175ea74a689b7145d309617eefbe2ea27e4fce422e01369eff6", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:86d2ff781f93e1de17122ebc514d5e64fcb63fed15941f496d7e146c6dcc7a49", "translated_from_revision": null}, "body_sha256": "e9b6b76b822cd53899160a92ca221eddadf17b0e862cf373789942709bf1490b", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/12/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/12/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "12", "link_map": {"/zh/docs/12/sql-explain.html": "/docs/12/sql-explain.html", "/zh/docs/12/performance-tips.html#USING-EXPLAIN": "/docs/12/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/12/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/12/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "4d7c69dec0103b94fe30e84cc4ee2c7a23463aad43b0fc8f2b6a9337654ed8db", "content_hash": "6c63531ff5e84c401044c504535f203b66543f4bb15eea92526894351d31c8b7", "source_database": "center", "source_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/12/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/12/facts/0/label": "Core node tag", "/versions/12/facts/1/label": "Structured EXPLAIN Node Type", "/versions/12/facts/2/label": "Inputs", "/versions/12/facts/2/value": "Provider-defined plan, possibly with children", "/versions/12/facts/3/label": "Output", "/versions/12/facts/3/value": "Provider-defined tuples", "/versions/12/facts/4/label": "Executor initializer", "/versions/12/facts/5/label": "Memory mechanism", "/versions/12/tables/0/title": "EXPLAIN labels in this source build", "/versions/12/related/1/label": "Using EXPLAIN", "/versions/12/related/2/label": "Parallel plans", "/versions/12/sections/0/title": "EXPLAIN names and attributes", "/versions/12/sections/1/title": "Memory and temporary storage", "/versions/12/sections/2/title": "Parallel execution and instrumentation", "/versions/12/sections/3/title": "Executor implementation notes", "/versions/12/sections/4/title": "EXPLAIN identity in core source", "/versions/12/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/12/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/12/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/12/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/12/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/12/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/12/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/12/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/12/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/12/sections/3/paragraphs/2": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/12/sections/3/paragraphs/3": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/12/tables/0/columns/0/label": "Text-format label", "/versions/12/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "369d537b6363d35c8839b4a6e9e7df7d41e9c378a1592848836b533bd0516435", "canonical_center_text_hash": "6c63531ff5e84c401044c504535f203b66543f4bb15eea92526894351d31c8b7"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/12/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/12/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "13": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": 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Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=13", "label": "EXPLAIN"}, {"url": "/docs/13/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/13/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 13.23 source archive", "label": "13.23", "major": "13", "channel": "historical", "revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6", "source_url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "line": 1259, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1259", "sha256": "541713e0e7f1c9cc352c2b6028964d440c19d2678a4463000094c24a88c1e730", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, {"url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "line": 282, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:282", "sha256": "d085ee99acfa00587e6ade3a1d9f8108a0566beedbbee3f54a50c9fc0cc2e875", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, {"url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "dfd00332b687df2770c0e85648d9ead66af89a48c9cc30830b6ac73e27196602", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, {"url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "dcb296833777b02008c4b6bae8e8f7c6423b7ffba21f36702597c9d596d039ab", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/13/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "13", "build_id": 66, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "d7400476f3cf658423dd2d2f64b6b6b0e53d8fdc8692b9e93a05587095d469e1", "fragment_sha256": "9385d1b095126378694216a1f9cb95d249ccc7fab5ffa3f65cf08679fe2b14c3", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": 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[{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "13", "text_hash": "c99737ee6e601ae0059110bab5db32990dc4e8a68cdd36a2765388aefb941d4a", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/13/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "13", "build_id": 66, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "d7400476f3cf658423dd2d2f64b6b6b0e53d8fdc8692b9e93a05587095d469e1", "fragment_sha256": "9385d1b095126378694216a1f9cb95d249ccc7fab5ffa3f65cf08679fe2b14c3", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:a13a825c39f0268ef1cfe9137e283e38d0da73b2d7894f0733c7b26372a4f6a4", "translated_from_revision": null}, "body_sha256": "510478d711226287bb45fa4adf88666075e792384dc3a4aeba14bc4b0d636fa4", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/13/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/13/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "13", "link_map": {"/zh/docs/13/sql-explain.html": "/docs/13/sql-explain.html", "/zh/docs/13/performance-tips.html#USING-EXPLAIN": "/docs/13/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/13/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/13/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "a0999c4f935c566b7b0b4672a2f4469d53c6be56bc5c12d9e2ad950a43c1f5eb", "content_hash": "c99737ee6e601ae0059110bab5db32990dc4e8a68cdd36a2765388aefb941d4a", "source_database": "center", "source_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/13/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/13/facts/0/label": "Core node tag", "/versions/13/facts/1/label": "Structured EXPLAIN Node Type", "/versions/13/facts/2/label": "Inputs", "/versions/13/facts/2/value": "Provider-defined plan, possibly with children", "/versions/13/facts/3/label": "Output", "/versions/13/facts/3/value": "Provider-defined tuples", "/versions/13/facts/4/label": "Executor initializer", "/versions/13/facts/5/label": "Memory mechanism", "/versions/13/tables/0/title": "EXPLAIN labels in this source build", "/versions/13/related/1/label": "Using EXPLAIN", "/versions/13/related/2/label": "Parallel plans", "/versions/13/sections/0/title": "EXPLAIN names and attributes", "/versions/13/sections/1/title": "Memory and temporary storage", "/versions/13/sections/2/title": "Parallel execution and instrumentation", "/versions/13/sections/3/title": "Executor implementation notes", "/versions/13/sections/4/title": "EXPLAIN identity in core source", "/versions/13/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/13/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/13/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/13/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/13/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/13/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/13/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/13/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/13/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/13/sections/3/paragraphs/2": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/13/sections/3/paragraphs/3": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/13/tables/0/columns/0/label": "Text-format label", "/versions/13/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "526b9cc2e222504b8d09b4a7211dcd30aa6507eb71048956ce70ad28a2ac4195", "canonical_center_text_hash": "c99737ee6e601ae0059110bab5db32990dc4e8a68cdd36a2765388aefb941d4a"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/13/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/13/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "14": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "87081dfab21e068c319cb66880ec680a20f96930fd94f59106cc3d6a647931e7", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=14", "label": "EXPLAIN"}, {"url": "/docs/14/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/14/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 14.24 source archive", "label": "14.24", "major": "14", "channel": "stable", "revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897", "source_url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "line": 1298, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1298", "sha256": "e091be4e2a083b8dea39ccd09beedede22c1716ef974da66c214a44f48be8c41", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, {"url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "72da1c5ad457f1d92a39ab73531701794df858419e3b89d6e6cb7079634e68fa", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, {"url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "87081dfab21e068c319cb66880ec680a20f96930fd94f59106cc3d6a647931e7", "archive_sha256": 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"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:87e6aa4fd6e1ec85c5f4a6de4f5647cfd9e5de734ca2c266d32b6d6192c662ef", "translated_from_revision": null}, "body_sha256": "7169149b82c0058fbc6cd28fcf8c2cb75a76e3081b4d2284be058537f5bb79b6", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "14", "text_hash": "5adf3ca0e5e4374e8040963ac1f64008ee1a106f4d1a7c284a5a93d5e877d92b", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/14/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "14", "build_id": 99, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "62cadce9a200c7891b3bbf04fc22c8dc17b4525aec0d020a074310592666f6d4", "fragment_sha256": "44f0e04fca33c2837461b83f68b9337a6abf37b979c0097630f9ab322fb3c567", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:87e6aa4fd6e1ec85c5f4a6de4f5647cfd9e5de734ca2c266d32b6d6192c662ef", "translated_from_revision": null}, "body_sha256": "7169149b82c0058fbc6cd28fcf8c2cb75a76e3081b4d2284be058537f5bb79b6", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/14/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/14/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "14", "link_map": {"/zh/docs/14/sql-explain.html": "/docs/14/sql-explain.html", "/zh/docs/14/performance-tips.html#USING-EXPLAIN": "/docs/14/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/14/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/14/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "fdb5428c8a26eb7ef9294b221fe0d113b148fd3ad2d897bcd6d39e77ef73c2be", "content_hash": "5adf3ca0e5e4374e8040963ac1f64008ee1a106f4d1a7c284a5a93d5e877d92b", "source_database": "center", "source_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/14/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/14/facts/0/label": "Core node tag", "/versions/14/facts/1/label": "Structured EXPLAIN Node Type", "/versions/14/facts/2/label": "Inputs", "/versions/14/facts/2/value": "Provider-defined plan, possibly with children", "/versions/14/facts/3/label": "Output", "/versions/14/facts/3/value": "Provider-defined tuples", "/versions/14/facts/4/label": "Executor initializer", "/versions/14/facts/5/label": "Memory mechanism", "/versions/14/tables/0/title": "EXPLAIN labels in this source build", "/versions/14/related/1/label": "Using EXPLAIN", "/versions/14/related/2/label": "Parallel plans", "/versions/14/sections/0/title": "EXPLAIN names and attributes", "/versions/14/sections/1/title": "Memory and temporary storage", "/versions/14/sections/2/title": "Parallel execution and instrumentation", "/versions/14/sections/3/title": "Executor implementation notes", "/versions/14/sections/4/title": "EXPLAIN identity in core source", "/versions/14/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/14/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/14/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/14/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/14/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/14/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/14/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/14/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/14/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/14/sections/3/paragraphs/2": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/14/sections/3/paragraphs/3": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/14/tables/0/columns/0/label": "Text-format label", "/versions/14/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "6da76be92543bc3592588b0e5a0a698884ad6ff7a8a10e0dc1073bceb5fbd009", "canonical_center_text_hash": "5adf3ca0e5e4374e8040963ac1f64008ee1a106f4d1a7c284a5a93d5e877d92b"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/14/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/14/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "15": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": 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Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=15", "label": "EXPLAIN"}, {"url": "/docs/15/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/15/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 15.19 source archive", "label": "15.19", "major": "15", "channel": "stable", "revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89", "source_url": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": 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"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:6bce1a2df9170cb1146a1411c5547190856638221a6539e618ee1016c9f493ad", "translated_from_revision": null}, "body_sha256": "4aaaac835d7b0918972dbd16cad3258a5aacf4a89c1493241961074962a9748a", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], 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["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "15", "text_hash": "d936b287b09e95d1f00ac3e7c6757040f31bf0b793c6fe74d3d26153696997f8", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/15/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "15", "build_id": 101, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "d842974e11d60f39bee19269d456c1cf6a01bc6c2c3ac27d8d1e7966ef5f46b9", "fragment_sha256": "16561716621b0c2403eaa78c0cd62211754eaec8fd5716f685f693e1deb3a07b", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:6bce1a2df9170cb1146a1411c5547190856638221a6539e618ee1016c9f493ad", "translated_from_revision": null}, "body_sha256": "4aaaac835d7b0918972dbd16cad3258a5aacf4a89c1493241961074962a9748a", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/15/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/15/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "15", "link_map": {"/zh/docs/15/sql-explain.html": "/docs/15/sql-explain.html", "/zh/docs/15/performance-tips.html#USING-EXPLAIN": "/docs/15/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/15/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/15/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "940278a6132861692d4e69534c7b8a44aea9903123e17a4ee31f8110ea0c399a", "content_hash": "d936b287b09e95d1f00ac3e7c6757040f31bf0b793c6fe74d3d26153696997f8", "source_database": "center", "source_revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/15/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/15/facts/0/label": "Core node tag", "/versions/15/facts/1/label": "Structured EXPLAIN Node Type", "/versions/15/facts/2/label": "Inputs", "/versions/15/facts/2/value": "Provider-defined plan, possibly with children", "/versions/15/facts/3/label": "Output", "/versions/15/facts/3/value": "Provider-defined tuples", "/versions/15/facts/4/label": "Executor initializer", "/versions/15/facts/5/label": "Memory mechanism", "/versions/15/tables/0/title": "EXPLAIN labels in this source build", "/versions/15/related/1/label": "Using EXPLAIN", "/versions/15/related/2/label": "Parallel plans", "/versions/15/sections/0/title": "EXPLAIN names and attributes", "/versions/15/sections/1/title": "Memory and temporary storage", "/versions/15/sections/2/title": "Parallel execution and instrumentation", "/versions/15/sections/3/title": "Executor implementation notes", "/versions/15/sections/4/title": "EXPLAIN identity in core source", "/versions/15/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/15/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/15/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/15/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/15/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/15/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/15/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/15/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/15/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/15/sections/3/paragraphs/2": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/15/sections/3/paragraphs/3": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/15/tables/0/columns/0/label": "Text-format label", "/versions/15/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "15676bb4ddc2c329d06e49d479dbb010ec4fa303f263c1356f310470fa7b302e", "canonical_center_text_hash": "d936b287b09e95d1f00ac3e7c6757040f31bf0b793c6fe74d3d26153696997f8"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/15/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/15/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "16": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "6baff2c85041e5a755b5fdb8f8026f4f41bfae92e4f8b932ec2e5a853736405f", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=16", "label": "EXPLAIN"}, {"url": "/docs/16/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/16/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 16.15 source archive", "label": "16.15", "major": "16", "channel": "stable", "revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed", "source_url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "line": 1334, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1334", "sha256": "8e017f0116dbea471339b40c37a667cc9f95039e7e0329c783e5e8ce194de7e1", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "e48c08e555f8cb4e4bb43df516c4b8906ce9bc374b2a745d98a1fc8c22cc5099", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "6baff2c85041e5a755b5fdb8f8026f4f41bfae92e4f8b932ec2e5a853736405f", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "97db47353db76326b874589a5ad0a04501cc74cd72e237e7bd956e7472c41f1f", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/16/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "16", "build_id": 103, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "394de9d6895c7909a1a823408b8c980c5415db8ca3c212e23d6e7e9b6e01c6cc", "fragment_sha256": "8a4cc7ad0a2c8ca5894434db8a1fca93a69bfb200ac510843c26d7bd42a12d58", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:80579a071736780f9c4022bb5148e1fb1256f1a33591306af67816e9e9bf3a9b", "translated_from_revision": null}, "body_sha256": "c7fc5556ac15645be25423b5ae5c1a6b7a22ba31e6d917682b5ef72a9bb953a8", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "16", "text_hash": "8e2dc1817694a3619a9f45945ae7279b2a10e7066593564f2e0ad8f8e1f6e2e5", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/16/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "16", "build_id": 103, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "394de9d6895c7909a1a823408b8c980c5415db8ca3c212e23d6e7e9b6e01c6cc", "fragment_sha256": "8a4cc7ad0a2c8ca5894434db8a1fca93a69bfb200ac510843c26d7bd42a12d58", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:80579a071736780f9c4022bb5148e1fb1256f1a33591306af67816e9e9bf3a9b", "translated_from_revision": null}, "body_sha256": "c7fc5556ac15645be25423b5ae5c1a6b7a22ba31e6d917682b5ef72a9bb953a8", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/16/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/16/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "16", "link_map": {"/zh/docs/16/sql-explain.html": "/docs/16/sql-explain.html", "/zh/docs/16/using-explain.html": "/docs/16/using-explain.html"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/16/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/16/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "e303c72b4216646e1dffff40355c82aef8243f0918902a987672143c3deabbc0", "content_hash": "8e2dc1817694a3619a9f45945ae7279b2a10e7066593564f2e0ad8f8e1f6e2e5", "source_database": "center", "source_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/16/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/16/facts/0/label": "Core node tag", "/versions/16/facts/1/label": "Structured EXPLAIN Node Type", "/versions/16/facts/2/label": "Inputs", "/versions/16/facts/2/value": "Provider-defined plan, possibly with children", "/versions/16/facts/3/label": "Output", "/versions/16/facts/3/value": "Provider-defined tuples", "/versions/16/facts/4/label": "Executor initializer", "/versions/16/facts/5/label": "Memory mechanism", "/versions/16/tables/0/title": "EXPLAIN labels in this source build", "/versions/16/related/1/label": "Using EXPLAIN", "/versions/16/related/2/label": "Parallel plans", "/versions/16/sections/0/title": "EXPLAIN names and attributes", "/versions/16/sections/1/title": "Memory and temporary storage", "/versions/16/sections/2/title": "Parallel execution and instrumentation", "/versions/16/sections/3/title": "Executor implementation notes", "/versions/16/sections/4/title": "EXPLAIN identity in core source", "/versions/16/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/16/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/16/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/16/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/16/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/16/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/16/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/16/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/16/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/16/sections/3/paragraphs/2": "Use a custom slot if specified in CustomScanState or use virtual slot otherwise.", "/versions/16/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/16/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/16/tables/0/columns/0/label": "Text-format label", "/versions/16/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "e9b9db6b858f2a07b01d680e918365d43eaa8d5b4b3ac3730e291d8f3d8242c5", "canonical_center_text_hash": "8e2dc1817694a3619a9f45945ae7279b2a10e7066593564f2e0ad8f8e1f6e2e5"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/16/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/16/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "17": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "3a0b348efe78c7a0f4ca785f235b244b2d6a54989ed9892742d74e4548e327a9", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=17", "label": "EXPLAIN"}, {"url": "/docs/17/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/17/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 17.11 source archive", "label": "17.11", "major": "17", "channel": "stable", "revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979", "source_url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "line": 1523, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1523", "sha256": "741251b1a3b6d269a52a673d42eb63b02e13a5872db7b359b137086ab21b63c8", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "a77576e158b94cb01fa8c5174ba133004eabdd727660323f8afc66c8d2e757b8", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "3a0b348efe78c7a0f4ca785f235b244b2d6a54989ed9892742d74e4548e327a9", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "d390dd69e2d3f5085beb42b33e46ff0676a2959b916a12b82118a7e545f8e562", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/17/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "17", "build_id": 105, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "b1252952c6d796f5e38c223b74ff667f2d19d677dcf85fe5269b782b830e5013", "fragment_sha256": "8f5243c368dfae57e826af49b7461d37d7f4d97207bd5f540aebe6b10a61f883", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:7340767258d21c21b36f373f1fff6bab2be18e0daca13a865129db6105c09efd", "translated_from_revision": null}, "body_sha256": "65369c74548bffda74bb8da458c8381e9fd02b5a9b4ea0624d402782c3ddd015", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "17", "text_hash": "8c552dbc3c05aed2f23fc2ac978b4ae8e2589ed8a10a77dcf3f4cc014a8fc23d", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/17/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "17", "build_id": 105, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "b1252952c6d796f5e38c223b74ff667f2d19d677dcf85fe5269b782b830e5013", "fragment_sha256": "8f5243c368dfae57e826af49b7461d37d7f4d97207bd5f540aebe6b10a61f883", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:7340767258d21c21b36f373f1fff6bab2be18e0daca13a865129db6105c09efd", "translated_from_revision": null}, "body_sha256": "65369c74548bffda74bb8da458c8381e9fd02b5a9b4ea0624d402782c3ddd015", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/17/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v17 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/17/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "17", "link_map": {"/zh/docs/17/sql-explain.html": "/docs/17/sql-explain.html", "/zh/docs/17/using-explain.html": "/docs/17/using-explain.html"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/17/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v17 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/17/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "2f57df9ad9c30d9fa19c82afa0d200a0fabc42c43fe674012074c8a646ea009c", "content_hash": "8c552dbc3c05aed2f23fc2ac978b4ae8e2589ed8a10a77dcf3f4cc014a8fc23d", "source_database": "center", "source_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/17/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/17/facts/0/label": "Core node tag", "/versions/17/facts/1/label": "Structured EXPLAIN Node Type", "/versions/17/facts/2/label": "Inputs", "/versions/17/facts/2/value": "Provider-defined plan, possibly with children", "/versions/17/facts/3/label": "Output", "/versions/17/facts/3/value": "Provider-defined tuples", "/versions/17/facts/4/label": "Executor initializer", "/versions/17/facts/5/label": "Memory mechanism", "/versions/17/tables/0/title": "EXPLAIN labels in this source build", "/versions/17/related/1/label": "Using EXPLAIN", "/versions/17/related/2/label": "Parallel plans", "/versions/17/sections/0/title": "EXPLAIN names and attributes", "/versions/17/sections/1/title": "Memory and temporary storage", "/versions/17/sections/2/title": "Parallel execution and instrumentation", "/versions/17/sections/3/title": "Executor implementation notes", "/versions/17/sections/4/title": "EXPLAIN identity in core source", "/versions/17/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/17/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/17/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/17/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/17/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/17/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/17/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/17/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/17/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/17/sections/3/paragraphs/2": "Use a custom slot if specified in CustomScanState or use virtual slot otherwise.", "/versions/17/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/17/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/17/tables/0/columns/0/label": "Text-format label", "/versions/17/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "1e5e5b0072ab43e4828f3765d637a73fdfc44daea03bd0e4c78f6aa07da18bb4", "canonical_center_text_hash": "8c552dbc3c05aed2f23fc2ac978b4ae8e2589ed8a10a77dcf3f4cc014a8fc23d"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/17/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v17 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/17/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "18": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "8827a109e7111830daadc159c1f37519f8856040c3bd194f8055b379f7c34dff", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=18", "label": "EXPLAIN"}, {"url": "/docs/18/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/18/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 18.6 source archive", "label": "18.6", "major": "18", "channel": "stable", "revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f", "source_url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 1508, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1508", "sha256": "34c86d6070224a0e981efef51f79101d6d505e5874f1684ace183034bab14bb4", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "f8a06a3f539077249b20664b2812433db6d7bd12b2c0ca633525db43d06f112a", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "8827a109e7111830daadc159c1f37519f8856040c3bd194f8055b379f7c34dff", "archive_sha256": 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"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b", "translated_from_revision": null}, "body_sha256": "3db5f10c1078d023b90f542be4ca0a647e045062ca61b08406da56cc640544eb", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "18", "text_hash": "65d4d83d9484582e3a84010cb64d443290cf873f56d9f2c95bf73438c7db7dd7", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/18/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "18", "build_id": 107, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "d2f749744b3ac5aa2eb0154f295e8163903cd20fcc130c74c6172cdf2ae3a9df", "fragment_sha256": "15fbdf84b8f499253ade4f4a5841de138619a9933b93cc241d431dbe922fa40c", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b", "translated_from_revision": null}, "body_sha256": "3db5f10c1078d023b90f542be4ca0a647e045062ca61b08406da56cc640544eb", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/18/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "18", "link_map": {"/zh/docs/18/sql-explain.html": "/docs/18/sql-explain.html", "/zh/docs/18/using-explain.html": "/docs/18/using-explain.html"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "9799d8e1f7198c60a0d7e2ef561a359f242e9f5c6c573ada3bb8fbe2e20530f8", "content_hash": "65d4d83d9484582e3a84010cb64d443290cf873f56d9f2c95bf73438c7db7dd7", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/18/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/18/facts/0/label": "Core node tag", "/versions/18/facts/1/label": "Structured EXPLAIN Node Type", "/versions/18/facts/2/label": "Inputs", "/versions/18/facts/2/value": "Provider-defined plan, possibly with children", "/versions/18/facts/3/label": "Output", "/versions/18/facts/3/value": "Provider-defined tuples", "/versions/18/facts/4/label": "Executor initializer", "/versions/18/facts/5/label": "Memory mechanism", "/versions/18/tables/0/title": "EXPLAIN labels in this source build", "/versions/18/related/1/label": "Using EXPLAIN", "/versions/18/related/2/label": "Parallel plans", "/versions/18/sections/0/title": "EXPLAIN names and attributes", "/versions/18/sections/1/title": "Memory and temporary storage", "/versions/18/sections/2/title": "Parallel execution and instrumentation", "/versions/18/sections/3/title": "Executor implementation notes", "/versions/18/sections/4/title": "EXPLAIN identity in core source", "/versions/18/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/18/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/18/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/18/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/18/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/18/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/18/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/18/sections/3/paragraphs/2": "Use a custom slot if specified in CustomScanState or use virtual slot otherwise.", "/versions/18/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/18/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/18/tables/0/columns/0/label": "Text-format label", "/versions/18/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "c6fc9f48c0d0b85b79ee450aa1f4658ba4946badd825989c2a386a94fe052fb7", "canonical_center_text_hash": "65d4d83d9484582e3a84010cb64d443290cf873f56d9f2c95bf73438c7db7dd7"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "center_zh_rendered": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/docs/18/sql-explain.html\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "19": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "14e15c695c41a8f5c6ccef43295b6626abf5718609e1204c3662c85064016dae", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=19", "label": "EXPLAIN"}, {"url": "/docs/19/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/19/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 19rc1 source archive", "label": "19rc1", "major": "19", "channel": "preview", "revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701", "source_url": "https://ftp.postgresql.org/pub/source/v19rc1/postgresql-19rc1.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v19rc1/postgresql-19rc1.tar.bz2", "line": 1520, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1520", "sha256": "8b115b1c194a4b54ae630209a741e293b1df49a9052f10b2de9ca092a48998e3", "archive_sha256": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, {"url": "https://ftp.postgresql.org/pub/source/v19rc1/postgresql-19rc1.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "5e39b2037bed672da55104229ecc32da5abde44c26bcad01479edcfa044d09ed", "archive_sha256": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, {"url": "https://ftp.postgresql.org/pub/source/v19rc1/postgresql-19rc1.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "14e15c695c41a8f5c6ccef43295b6626abf5718609e1204c3662c85064016dae", "archive_sha256": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, {"url": "https://ftp.postgresql.org/pub/source/v19rc1/postgresql-19rc1.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "8d7bcf0e3b0d990a7bf35af47099d6d77207594b3136ff17104ed80bfaa47022", "archive_sha256": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/19/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "19", "build_id": 109, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "9bbb1ef5924e4788a3dc2642828383c67ab8651fb6b0e45924c454f095b0ff47", "fragment_sha256": "1ceb32499da15c4bcec0644765b693adbc1991296745e00460ce28d06d701ef3", "source_revision": "sha256:af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:65fda1f1b62a89992b84014c9157e61b67dbe8190e93945826efec668fad038c", "translated_from_revision": "sha256:af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "body_sha256": "f38ed16282da5aaa49c0d2cbdd9b13824d4d5269d9c79f423ed6df279a74e28f", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "19", "text_hash": "9ef50c0d97f807e121754a6444dd3254343dc49f4325f5f79e70cec3e7731396", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/19/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "19", "build_id": 109, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "9bbb1ef5924e4788a3dc2642828383c67ab8651fb6b0e45924c454f095b0ff47", "fragment_sha256": "1ceb32499da15c4bcec0644765b693adbc1991296745e00460ce28d06d701ef3", "source_revision": "sha256:af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:65fda1f1b62a89992b84014c9157e61b67dbe8190e93945826efec668fad038c", "translated_from_revision": "sha256:af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "body_sha256": "f38ed16282da5aaa49c0d2cbdd9b13824d4d5269d9c79f423ed6df279a74e28f", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/19/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/19/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "19", "link_map": {"/zh/docs/19/sql-explain.html": "/docs/19/sql-explain.html", "/zh/docs/19/using-explain.html": "/docs/19/using-explain.html"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/19/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/19/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "acf9f51a1b880cfed7006a7ad52073024d1ed30f89a72944eb8ef59dd90336b0", "content_hash": "9ef50c0d97f807e121754a6444dd3254343dc49f4325f5f79e70cec3e7731396", "source_database": "center", "source_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/19/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/19/facts/0/label": "Core node tag", "/versions/19/facts/1/label": "Structured EXPLAIN Node Type", "/versions/19/facts/2/label": "Inputs", "/versions/19/facts/2/value": "Provider-defined plan, possibly with children", "/versions/19/facts/3/label": "Output", "/versions/19/facts/3/value": "Provider-defined tuples", "/versions/19/facts/4/label": "Executor initializer", "/versions/19/facts/5/label": "Memory mechanism", "/versions/19/tables/0/title": "EXPLAIN labels in this source build", "/versions/19/related/1/label": "Using EXPLAIN", "/versions/19/related/2/label": "Parallel plans", "/versions/19/sections/0/title": "EXPLAIN names and attributes", "/versions/19/sections/1/title": "Memory and temporary storage", "/versions/19/sections/2/title": "Parallel execution and instrumentation", "/versions/19/sections/3/title": "Executor implementation notes", "/versions/19/sections/4/title": "EXPLAIN identity in core source", "/versions/19/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/19/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/19/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/19/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/19/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/19/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/19/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/19/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/19/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/19/sections/3/paragraphs/2": "Use a custom slot if specified in CustomScanState or use virtual slot otherwise.", "/versions/19/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/19/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/19/tables/0/columns/0/label": "Text-format label", "/versions/19/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "edc1191c0ce47759e3d8ed949849836f51bb7a7614dac33dee67258dc7c0151d", "canonical_center_text_hash": "9ef50c0d97f807e121754a6444dd3254343dc49f4325f5f79e70cec3e7731396"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/19/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/19/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "source_revalidation": {"kind": "static-same-version-source-and-manual-replay", "audit": "wiki-audit-20261023", "runtime_rerun": false, "compared_fields": "entity membership and source-derived facts; presentation markup normalized", "source_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701", "previous_source_revision": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}}, "20": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "14e15c695c41a8f5c6ccef43295b6626abf5718609e1204c3662c85064016dae", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=20", "label": "EXPLAIN"}, {"url": "/docs/devel/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/devel/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 20devel source archive", "label": "20devel", "major": "20", "channel": "devel", "revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac", "source_url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "line": 1520, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1520", "sha256": "f82f238e2e6e249e10daf2e257728494ec10de1695fcf05feaadfd7f6bf78600", "archive_sha256": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, {"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "5e39b2037bed672da55104229ecc32da5abde44c26bcad01479edcfa044d09ed", "archive_sha256": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, {"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "14e15c695c41a8f5c6ccef43295b6626abf5718609e1204c3662c85064016dae", "archive_sha256": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, {"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "aa3c27b465209c0ecd1f5e0186d39110a75ed7aafb9a196d483fccb5fc641c6b", "archive_sha256": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/devel/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "20", "build_id": 111, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "436517563e51b6d851ef143e70d01f5f68fe0a01e00a0d507e7bd79d7570aa25", "fragment_sha256": "f2d2c226e0479b8d931accead1f2cf7c1b8646afa24d8025ea5d5bcab837f779", "source_revision": "sha256:49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:98c980963b401d40bd50df72b909e7523e3148b8fdb48edd897de2efb67e5235", "translated_from_revision": "sha256:49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "body_sha256": "037ee5a88f8e165ed983c371ce60fe87ebda1afa35e8e340371ed1c619235d94", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "20", "text_hash": "6c2310874d23db55e432c1f8982a8a64f5492e926d1aadc780b847844f3d3e22", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/devel/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "20", "build_id": 111, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "436517563e51b6d851ef143e70d01f5f68fe0a01e00a0d507e7bd79d7570aa25", "fragment_sha256": "f2d2c226e0479b8d931accead1f2cf7c1b8646afa24d8025ea5d5bcab837f779", "source_revision": "sha256:49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:98c980963b401d40bd50df72b909e7523e3148b8fdb48edd897de2efb67e5235", "translated_from_revision": "sha256:49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "body_sha256": "037ee5a88f8e165ed983c371ce60fe87ebda1afa35e8e340371ed1c619235d94", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/devel/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/devel/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "20", "link_map": {"/zh/docs/devel/sql-explain.html": "/docs/devel/sql-explain.html", "/zh/docs/devel/using-explain.html": "/docs/devel/using-explain.html"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/devel/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/devel/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "a714dbbe9b4f74fbd908c2e4d99a78d91c59d32c2d975ec27e7036a99dab1e8b", "content_hash": "6c2310874d23db55e432c1f8982a8a64f5492e926d1aadc780b847844f3d3e22", "source_database": "center", "source_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/summary": "Executes a plan supplied by a custom-scan provider.", "/category": "Extensibility", "/versions/20/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/20/facts/0/label": "Core node tag", "/versions/20/facts/1/label": "Structured EXPLAIN Node Type", "/versions/20/facts/2/label": "Inputs", "/versions/20/facts/2/value": "Provider-defined plan, possibly with children", "/versions/20/facts/3/label": "Output", "/versions/20/facts/3/value": "Provider-defined tuples", "/versions/20/facts/4/label": "Executor initializer", "/versions/20/facts/5/label": "Memory mechanism", "/versions/20/tables/0/title": "EXPLAIN labels in this source build", "/versions/20/related/1/label": "Using EXPLAIN", "/versions/20/related/2/label": "Parallel plans", "/versions/20/sections/0/title": "EXPLAIN names and attributes", "/versions/20/sections/1/title": "Memory and temporary storage", "/versions/20/sections/2/title": "Parallel execution and instrumentation", "/versions/20/sections/3/title": "Executor implementation notes", "/versions/20/sections/4/title": "EXPLAIN identity in core source", "/versions/20/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/20/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/20/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/20/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/20/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/20/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/20/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/20/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/20/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/20/sections/3/paragraphs/2": "Use a custom slot if specified in CustomScanState or use virtual slot otherwise.", "/versions/20/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/20/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/20/tables/0/columns/0/label": "Text-format label", "/versions/20/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "a1de881d04143967729278eb51c9562d9b14afcce31a93be5a9939df78897550", "canonical_center_text_hash": "6c2310874d23db55e432c1f8982a8a64f5492e926d1aadc780b847844f3d3e22"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/devel/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/devel/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "source_revalidation": {"kind": "static-same-version-source-and-manual-replay", "audit": "wiki-audit-20261023", "runtime_rerun": false, "compared_fields": "entity membership and source-derived facts; presentation markup normalized", "source_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac", "previous_source_revision": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}}}}, "snapshot": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "8827a109e7111830daadc159c1f37519f8856040c3bd194f8055b379f7c34dff", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=18", "label": "EXPLAIN"}, {"url": "/docs/18/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/18/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 18.6 source archive", "label": "18.6", "major": "18", "channel": "stable", "revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f", "source_url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 1508, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1508", "sha256": "34c86d6070224a0e981efef51f79101d6d505e5874f1684ace183034bab14bb4", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 289, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:289", "sha256": "f8a06a3f539077249b20664b2812433db6d7bd12b2c0ca633525db43d06f112a", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "8827a109e7111830daadc159c1f37519f8856040c3bd194f8055b379f7c34dff", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "52422b327a8049fbbb20d8b96008a0fc0a6fafa60f7eff3c695d5b2e83830120", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/18/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "18", "build_id": 107, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "d2f749744b3ac5aa2eb0154f295e8163903cd20fcc130c74c6172cdf2ae3a9df", "fragment_sha256": "15fbdf84b8f499253ade4f4a5841de138619a9933b93cc241d431dbe922fa40c", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b", "translated_from_revision": null}, "body_sha256": "3db5f10c1078d023b90f542be4ca0a647e045062ca61b08406da56cc640544eb", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_CustomScan", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "CustomScan", "locale": "zh-Hans", "source": {"key": "custom-scan", "locale": "zh-Hans", "version": "18", "text_hash": "65d4d83d9484582e3a84010cb64d443290cf873f56d9f2c95bf73438c7db7dd7", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_CustomScan"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "Custom Scan"}, {"label": "\u8f93\u5165", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u8ba1\u5212\uff0c\u53ef\u80fd\u5305\u542b\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u63d0\u4f9b\u65b9\u5b9a\u4e49\u7684\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitCustomScan"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/18/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "18", "build_id": 107, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "d2f749744b3ac5aa2eb0154f295e8163903cd20fcc130c74c6172cdf2ae3a9df", "fragment_sha256": "15fbdf84b8f499253ade4f4a5841de138619a9933b93cc241d431dbe922fa40c", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b", "translated_from_revision": null}, "body_sha256": "3db5f10c1078d023b90f542be4ca0a647e045062ca61b08406da56cc640544eb", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/18/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "version": "18", "link_map": {"/zh/docs/18/sql-explain.html": "/docs/18/sql-explain.html", "/zh/docs/18/using-explain.html": "/docs/18/using-explain.html"}, "body_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "9799d8e1f7198c60a0d7e2ef561a359f242e9f5c6c573ada3bb8fbe2e20530f8", "content_hash": "65d4d83d9484582e3a84010cb64d443290cf873f56d9f2c95bf73438c7db7dd7", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "Custom Scan (%s)", "identity": "Custom Scan"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aCustom Scan (%s).", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1aExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeCustom.c\uff1a\u5904\u7406\u81ea\u5b9a\u4e49\u626b\u63cf\u8282\u70b9\u6267\u884c\u7684\u4f8b\u7a0b\u3002", "\u5206\u914d CustomScanState \u5bf9\u8c61\u3002\u7531\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u8c03\u7528 palloc\uff0c\u4ee5\u4fbf\u5b83\u53ef\u4ee5\u5206\u914d\u4e00\u4e2a\u66f4\u5927\u7684\u5bf9\u8c61\uff0c\u5e76\u5c06 CustomScanState \u5d4c\u5165\u4e3a\u9996\u5b57\u6bb5\u3002\u6b64\u65f6\u5fc5\u987b\u6b63\u786e\u8bbe\u7f6e\u8282\u70b9\u6807\u7b7e\u548c methods \u5b57\u6bb5\uff1b\u5176\u4ed6\u6807\u51c6\u5b57\u6bb5\u5e94\u7f6e\u96f6\u3002", "\u82e5 CustomScanState \u6307\u5b9a\u4e86\u81ea\u5b9a\u4e49\u69fd\u4f4d\u5219\u4f7f\u7528\u5b83\uff0c\u5426\u5219\u4f7f\u7528\u865a\u62df\u69fd\u4f4d\u3002", "\u786e\u5b9a\u626b\u63cf\u5143\u7ec4\u7684\u7c7b\u578b\u3002\u5982\u679c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7ed9\u51fa\u4e86\u63cf\u8ff0\u626b\u63cf\u5143\u7ec4\u7684\u76ee\u6807\u5217\u8868\uff0c\u5219\u4f7f\u7528\u8be5\u5217\u8868\uff1b\u5426\u5219\u4f7f\u7528\u57fa\u8868\u5173\u7cfb\u7684\u884c\u7c7b\u578b\u3002", "\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u7684\u56de\u8c03\u6309\u81ea\u8eab\u903b\u8f91\u5b8c\u6210\u81ea\u5b9a\u4e49\u626b\u63cf\u72b6\u6001\u8282\u70b9\u7684\u6700\u540e\u521d\u59cb\u5316\u3002"]}, {"code": "case T_CustomScan:\n\t\t\tsname = \"Custom Scan\";\n\t\t\tcustom_name = ((CustomScan *) plan)->methods->CustomName;\n\t\t\tif (custom_name)\n\t\t\t\tpname = psprintf(\"Custom Scan (%s)\", custom_name);\n\t\t\telse\n\t\t\t\tpname = sname;\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/18/description/0": "Executes a plan supplied by a custom-scan provider.", "/versions/18/facts/0/label": "Core node tag", "/versions/18/facts/1/label": "Structured EXPLAIN Node Type", "/versions/18/facts/2/label": "Inputs", "/versions/18/facts/2/value": "Provider-defined plan, possibly with children", "/versions/18/facts/3/label": "Output", "/versions/18/facts/3/value": "Provider-defined tuples", "/versions/18/facts/4/label": "Executor initializer", "/versions/18/facts/5/label": "Memory mechanism", "/versions/18/tables/0/title": "EXPLAIN labels in this source build", "/versions/18/related/1/label": "Using EXPLAIN", "/versions/18/related/2/label": "Parallel plans", "/versions/18/sections/0/title": "EXPLAIN names and attributes", "/versions/18/sections/1/title": "Memory and temporary storage", "/versions/18/sections/2/title": "Parallel execution and instrumentation", "/versions/18/sections/3/title": "Executor implementation notes", "/versions/18/sections/4/title": "EXPLAIN identity in core source", "/versions/18/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/18/sections/0/paragraphs/1": "Text names recorded by this source: Custom Scan (%s).", "/versions/18/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/18/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/18/sections/2/paragraphs/1": "Callbacks in this build: ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM.", "/versions/18/sections/3/paragraphs/0": "nodeCustom.c Routines to handle execution of custom scan node", "/versions/18/sections/3/paragraphs/1": "Allocate the CustomScanState object. We let the custom scan provider do the palloc, in case it wants to make a larger object that embeds CustomScanState as the first field. It must set the node tag and the methods field correctly at this time. Other standard fields should be set to zero.", "/versions/18/sections/3/paragraphs/2": "Use a custom slot if specified in CustomScanState or use virtual slot otherwise.", "/versions/18/sections/3/paragraphs/3": "Determine the scan tuple type. If the custom scan provider provided a targetlist describing the scan tuples, use that; else use base relation's rowtype.", "/versions/18/sections/3/paragraphs/4": "The callback of custom-scan provider applies the final initialization of the custom-scan-state node according to its logic.", "/versions/18/tables/0/columns/0/label": "Text-format label", "/versions/18/tables/0/columns/1/label": "Structured node identity"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "c6fc9f48c0d0b85b79ee450aa1f4658ba4946badd825989c2a386a94fe052fb7", "canonical_center_text_hash": "65d4d83d9484582e3a84010cb64d443290cf873f56d9f2c95bf73438c7db7dd7"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "description_zh": "\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002", "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"]}, "comparison_hash": "c905b2ddadbea858aa4811fa7d15ee0733e3c82e2ac2c9fad827846072b5c975", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeCustom.c"}, "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", "ExecCustomScanReInitializeDSM"], "description_zh_html": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "center_zh_rendered": "<p>\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u8005\u751f\u6210\u7684\u8ba1\u5212\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_CustomScan</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>Custom Scan (%s)</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a<code>ExecCustomScanEstimate, ExecCustomScanInitializeDSM, ExecCustomScanInitializeWorker, ExecCustomScanReInitializeDSM</code>\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/docs/18/sql-explain.html\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "comparison": {"left": "17", "right": "18", "status": "unchanged", "diff": ""}}