{"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\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002", "aliases": ["Custom Scan (%s)", "CustomScan", "T_CustomScan"], "content_hash": "1a4cd4f0cecb2d141c42619c86b7105e9f838bb1ec8a004499c3fabffab0042a", "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": "\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", "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": 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"94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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/v11.22/postgresql-11.22.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "c1ff93e80239f360e9346f146778909edad35a2084d809a5d728e0a60206a645", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}], "mechanism": "unclassified", "description": "\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", "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=11", "label": "EXPLAIN"}, {"url": "/docs/11/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/11/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 11.22 source archive", "label": "11.22", "major": "11", "channel": "historical", "revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0", "source_url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "line": 1130, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1130", "sha256": "9df8400c1a4377179572ceb916d6020fca4e2760f74bf416d77ed97476523bbd", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "line": 282, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:282", "sha256": "95ef4d4a5df4c29f14af9763fae2c530449bdacdf3853d9ff297adf1fed6153b", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "c1ff93e80239f360e9346f146778909edad35a2084d809a5d728e0a60206a645", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "5e0511194183800e8d6eb293fd4b40639c7d3118e2d199c8e7865ba4fa4cf67f", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "12": {"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/v12.22/postgresql-12.22.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "11e5d4f6fa1448ea8337ffd89c05cdddb1c97864d0487eb4a5f57213d15a5a4d", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}], "mechanism": "unclassified", "description": "\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", "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=12", "label": "EXPLAIN"}, {"url": "/docs/12/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/12/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 12.22 source archive", "label": "12.22", "major": "12", "channel": "historical", "revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b", "source_url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "line": 1201, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1201", "sha256": "d02ea84fdaa201de5d9360645a9f24bfbd2c31f7d45a639e09560ac0e6b6471d", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "line": 282, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:282", "sha256": "311b17379fe54e3f342fe5ad41c43afbdfa1b844978db2bb2eb22b82520d3256", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "11e5d4f6fa1448ea8337ffd89c05cdddb1c97864d0487eb4a5f57213d15a5a4d", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "b0c4a0aeb48660ce06e5e700d5529ca9066fd16682bd15783d6e71b5420b07b0", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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/v13.23/postgresql-13.23.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "dfd00332b687df2770c0e85648d9ead66af89a48c9cc30830b6ac73e27196602", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}], "mechanism": "unclassified", "description": "\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", "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"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", 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"\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": 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"302f51a16b570dba7ec4e7bc045f7df5800d21630280354d1a24025f3baec75d", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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/v15.19/postgresql-15.19.tar.bz2", "path": "src/backend/executor/nodeCustom.c", "label": "src/backend/executor/nodeCustom.c", "sha256": "0276e87b4b21a5e4e0d69d1b78339db86978de62fc2d21d450c5de8ac361e285", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}], "mechanism": "unclassified", "description": "\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", "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": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "line": 1301, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1301", "sha256": "bb3b442d0f1b098aa8707335250102f027a596cd94117308bd16d1d36b258f5c", "archive_sha256": 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"fb4a4c8165495299131173680bc02a950d88e1ff610231fd97997bc0c9afc1d7", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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", "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"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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", "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"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "comparison_data": {"node_tag": "T_CustomScan", "strategies": [], "text_names": ["Custom Scan (%s)"], "initializer": "ExecInitCustomScan", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": ["ExecCustomScanEstimate", "ExecCustomScanInitializeDSM", "ExecCustomScanInitializeWorker", 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"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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", "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 19beta4 source archive", "label": "19beta4", "major": "19", "channel": "preview", "revision": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86", "source_url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "line": 1520, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1520", "sha256": "8b115b1c194a4b54ae630209a741e293b1df49a9052f10b2de9ca092a48998e3", "archive_sha256": 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"1c65d5d6b6c81c71531685843647869bcae630779d815a5036b06e070c6c06c7", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "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": "\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", "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": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41", "source_url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "source_snapshot_utc": "26-Sep-2026 20:22"}, "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": "13402758013520451539427b5993db06d463ca11c4e2d4cc5444e82367688077", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, {"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": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, {"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"}, {"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": "7a94ed1652f0d74d50c39971d1cd3e8051dbc0d6058f31b6de71a433ca343521", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}}}, "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": "\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", "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"}], "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"}], "strategies": [], "description": ["\u6267\u884c\u81ea\u5b9a\u4e49\u626b\u63cf\u63d0\u4f9b\u65b9\u7ed9\u51fa\u7684\u8ba1\u5212\u3002"], "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"}, "evidence_kind": "source and documentation", "explain_names": ["Custom Scan (%s)"], "partial_modes": [], "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", "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"]}, "comparison": {"left": "17", "right": "18", "status": "unchanged", "diff": ""}}