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["\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u5185\u5b58\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u4e0a\u4e00\u8f6e\u5143\u7ec4\u5904\u7406\u4e2d\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002 \u5fc5\u987b\u7b49\u5230\u4ece\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u6240\u6709\u5143\u7ec4\u540e\u624d\u80fd\u91cd\u7f6e\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p> <span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/10/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/10/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "10", "link_map": {"/zh/docs/10/sql-explain.html": "/docs/10/sql-explain.html", "/zh/docs/10/performance-tips.html#USING-EXPLAIN": "/docs/10/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p> <span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/10/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/10/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "db61fee7b2ce2d1705a08cd4c22d10632369f5b497258ad5973b5ba2d7fbd097", "content_hash": "bf997ff15ed3f59dd020686df027604eda268b6396e1cd524a5de4136ae9ef93", "source_database": "center", "source_revision": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u5185\u5b58\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u4e0a\u4e00\u8f6e\u5143\u7ec4\u5904\u7406\u4e2d\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002 \u5fc5\u987b\u7b49\u5230\u4ece\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u6240\u6709\u5143\u7ec4\u540e\u624d\u80fd\u91cd\u7f6e\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/10/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/10/facts/3/label": "Output", "/versions/10/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/10/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/10/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/10/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/10/sections/3/paragraphs/3": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/versions/10/sections/3/paragraphs/4": "Reset per-tuple memory context to free any expression evaluation storage allocated in the previous tuple cycle. Note this can't happen until we're done projecting out tuples from a scan tuple.", "/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": "69e288e6641ba932338670c1a149f7ffbc5a28f0ad67ad188fc5d94d2b1decf8", "canonical_center_text_hash": "bf997ff15ed3f59dd020686df027604eda268b6396e1cd524a5de4136ae9ef93"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p> <span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/10/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/10/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "11": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "4f1807795b26e6fe08d44de4358662de20a1335d927e6d821d58da6142259214", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 1010, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1010", "sha256": "9df8400c1a4377179572ceb916d6020fca4e2760f74bf416d77ed97476523bbd", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "line": 169, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:169", "sha256": "95ef4d4a5df4c29f14af9763fae2c530449bdacdf3853d9ff297adf1fed6153b", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "path": "src/backend/executor/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "4f1807795b26e6fe08d44de4358662de20a1335d927e6d821d58da6142259214", "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"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/11/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "11", "build_id": 64, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "617a30102327f61276ba77fb034f4bf1bbb677d91d4eb5507dc14d740e6394c9", "fragment_sha256": "a7b71780192bea8bfc169883aae459f6d32a71fe928f60388479827c9c8b54bc", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:ef5c7bc074acae9795db16e6b7482aea3b222bd4bcce0f76831332b97a21e8a1", "translated_from_revision": null}, "body_sha256": "d9ead3386f48b7fdb20bdebfd2269a3f22f0532205391344ed2945e6fd8bc82f", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_ProjectSet", "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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "11", "text_hash": "80c0ca3458bce5fffc08df2389d0ad7177eacab481d7ca48e13634a475324b03", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/11/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "11", "build_id": 64, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "617a30102327f61276ba77fb034f4bf1bbb677d91d4eb5507dc14d740e6394c9", "fragment_sha256": "a7b71780192bea8bfc169883aae459f6d32a71fe928f60388479827c9c8b54bc", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:ef5c7bc074acae9795db16e6b7482aea3b222bd4bcce0f76831332b97a21e8a1", "translated_from_revision": null}, "body_sha256": "d9ead3386f48b7fdb20bdebfd2269a3f22f0532205391344ed2945e6fd8bc82f", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/11/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/11/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "11", "link_map": {"/zh/docs/11/sql-explain.html": "/docs/11/sql-explain.html", "/zh/docs/11/performance-tips.html#USING-EXPLAIN": "/docs/11/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/11/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/11/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "e62aa8e1d5b85223bd837faff752cecf541b8631a8b1d176f5f0ace1183ff7ab", "content_hash": "80c0ca3458bce5fffc08df2389d0ad7177eacab481d7ca48e13634a475324b03", "source_database": "center", "source_revision": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/11/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/11/facts/3/label": "Output", "/versions/11/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/11/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/11/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/11/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/11/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/11/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "8ff9838f22f85c90f84bd6909809130027ec9cff7b82a81e6f62544d50cd0c17", "canonical_center_text_hash": "80c0ca3458bce5fffc08df2389d0ad7177eacab481d7ca48e13634a475324b03"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/11/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/11/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "12": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "032cc3cc2eb98c0e6ae2dd015f92818ebab059935f77022d29e278acee2f90a6", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 1081, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1081", "sha256": "d02ea84fdaa201de5d9360645a9f24bfbd2c31f7d45a639e09560ac0e6b6471d", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "line": 169, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:169", "sha256": "311b17379fe54e3f342fe5ad41c43afbdfa1b844978db2bb2eb22b82520d3256", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "path": "src/backend/executor/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "032cc3cc2eb98c0e6ae2dd015f92818ebab059935f77022d29e278acee2f90a6", "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"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/12/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "12", "build_id": 65, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "773efea8d76bcea57eb449ceb506a51025a4125ceaa9b765a1039e558f5cfe98", "fragment_sha256": "5563b70cc4f15175ea74a689b7145d309617eefbe2ea27e4fce422e01369eff6", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:86d2ff781f93e1de17122ebc514d5e64fcb63fed15941f496d7e146c6dcc7a49", "translated_from_revision": null}, "body_sha256": "331a2070a05202afadd69ddc58391c435c69183514bff5627e4b98cba185d17c", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_ProjectSet", "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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "12", "text_hash": "45ab258d94a6f9fafb2db20c6bf9183aaef309e76ae4a9f05b4301c239ad4b8b", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/12/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "12", "build_id": 65, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "773efea8d76bcea57eb449ceb506a51025a4125ceaa9b765a1039e558f5cfe98", "fragment_sha256": "5563b70cc4f15175ea74a689b7145d309617eefbe2ea27e4fce422e01369eff6", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:86d2ff781f93e1de17122ebc514d5e64fcb63fed15941f496d7e146c6dcc7a49", "translated_from_revision": null}, "body_sha256": "331a2070a05202afadd69ddc58391c435c69183514bff5627e4b98cba185d17c", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/12/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/12/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "12", "link_map": {"/zh/docs/12/sql-explain.html": "/docs/12/sql-explain.html", "/zh/docs/12/performance-tips.html#USING-EXPLAIN": "/docs/12/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/12/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/12/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "a4498420850adc7417fc64cd133564db61769642d92e88c904e4853c5d87a7e1", "content_hash": "45ab258d94a6f9fafb2db20c6bf9183aaef309e76ae4a9f05b4301c239ad4b8b", "source_database": "center", "source_revision": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/12/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/12/facts/3/label": "Output", "/versions/12/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/12/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/12/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/12/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/12/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/12/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "b04a84b160bb4a39587d9ef8e2fecee75cc1060c44acd5036be7acf5ba1a70cc", "canonical_center_text_hash": "45ab258d94a6f9fafb2db20c6bf9183aaef309e76ae4a9f05b4301c239ad4b8b"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/12/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/12/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "13": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "20c52fcf08ee8d7114df2ada8bfc9f3d2c08cd3f025c3c371b6ccc20db86ee2e", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. 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"snapshot:sha256:a13a825c39f0268ef1cfe9137e283e38d0da73b2d7894f0733c7b26372a4f6a4", "translated_from_revision": null}, "body_sha256": "a3bf05eb1298c38eb4f40887906e8c4ff949902d7ae08750cdc0edfdba9c0ff2", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_ProjectSet", "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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "13", "text_hash": "737691a4034dfbe7d2bc2f1587df2abd5e8edf6bae79b35a4410eadf8830168d", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/13/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "13", "build_id": 66, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "d7400476f3cf658423dd2d2f64b6b6b0e53d8fdc8692b9e93a05587095d469e1", "fragment_sha256": "9385d1b095126378694216a1f9cb95d249ccc7fab5ffa3f65cf08679fe2b14c3", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "snapshot:sha256:a13a825c39f0268ef1cfe9137e283e38d0da73b2d7894f0733c7b26372a4f6a4", "translated_from_revision": null}, "body_sha256": "a3bf05eb1298c38eb4f40887906e8c4ff949902d7ae08750cdc0edfdba9c0ff2", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"xref\" href=\"/zh/docs/13/sql-explain.html\"><span class=\"refentrytitle\">EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/13/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "13", "link_map": {"/zh/docs/13/sql-explain.html": "/docs/13/sql-explain.html", "/zh/docs/13/performance-tips.html#USING-EXPLAIN": "/docs/13/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/13/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/13/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "d7db2bf21a6b1945ff4fd16a236940240bc03fdb8552dbbe8cca7a1c28aae69a", "content_hash": "737691a4034dfbe7d2bc2f1587df2abd5e8edf6bae79b35a4410eadf8830168d", "source_database": "center", "source_revision": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/13/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/13/facts/3/label": "Output", "/versions/13/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/13/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/13/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/13/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/13/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/13/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "77c87e7740e3b68bb1008d058ef962b719e8b50e298e6ed3ee4a280f6c1f207a", "canonical_center_text_hash": "737691a4034dfbe7d2bc2f1587df2abd5e8edf6bae79b35a4410eadf8830168d"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/13/sql-explain.html\" rel=\"nofollow\"><span>EXPLAIN</span></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/13/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "14": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": 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Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=14", "label": "EXPLAIN"}, {"url": "/docs/14/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/14/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 14.24 source archive", "label": "14.24", "major": "14", "channel": "stable", "revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897", "source_url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": 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["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "14", "text_hash": "69ae2ffbc2dbfb2f86c5bac55d78aba78cfdf7021d62da13c7b9af4b406ca595", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/14/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "14", "build_id": 99, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "62cadce9a200c7891b3bbf04fc22c8dc17b4525aec0d020a074310592666f6d4", "fragment_sha256": "44f0e04fca33c2837461b83f68b9337a6abf37b979c0097630f9ab322fb3c567", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:87e6aa4fd6e1ec85c5f4a6de4f5647cfd9e5de734ca2c266d32b6d6192c662ef", "translated_from_revision": null}, "body_sha256": "e75ae031eaa366ceebcd2d7dab7ee5290fb89804aad86c7703721c629de332d8", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/14/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/14/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "14", "link_map": {"/zh/docs/14/sql-explain.html": "/docs/14/sql-explain.html", "/zh/docs/14/performance-tips.html#USING-EXPLAIN": "/docs/14/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/14/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/14/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "d0560ff8bc049007335784243c3ddf5e0890fae7154c00b09fd626baf2d23009", "content_hash": "69ae2ffbc2dbfb2f86c5bac55d78aba78cfdf7021d62da13c7b9af4b406ca595", "source_database": "center", "source_revision": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/14/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/14/facts/3/label": "Output", "/versions/14/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/14/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/14/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/14/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/14/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/14/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "bc7417c14ffc220a1608d9d4e2b93550eeeb899f35f75816a97eb9059c1ae3e3", "canonical_center_text_hash": "69ae2ffbc2dbfb2f86c5bac55d78aba78cfdf7021d62da13c7b9af4b406ca595"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/14/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/14/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "15": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "07ef59ff006bd58f0c6f3b3363fa0909e2df44b6d6e673de805b1743cf001547", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 1175, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1175", "sha256": "bb3b442d0f1b098aa8707335250102f027a596cd94117308bd16d1d36b258f5c", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, {"url": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "line": 171, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:171", "sha256": "19836c50a272741a4eac653541e655437c2e00710a541e5348d6a277d0669d7c", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, {"url": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "path": "src/backend/executor/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "07ef59ff006bd58f0c6f3b3363fa0909e2df44b6d6e673de805b1743cf001547", "archive_sha256": 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["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", 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"T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/15/performance-tips.html#USING-EXPLAIN", "anchor": "USING-EXPLAIN", "locale": "zh-Hans", "version": "15", "build_id": 101, "page_key": "performance-tips.html", "extraction": "concept-introduction", "source_hash": "d842974e11d60f39bee19269d456c1cf6a01bc6c2c3ac27d8d1e7966ef5f46b9", "fragment_sha256": "16561716621b0c2403eaa78c0cd62211754eaec8fd5716f685f693e1deb3a07b", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:6bce1a2df9170cb1146a1411c5547190856638221a6539e618ee1016c9f493ad", "translated_from_revision": null}, "body_sha256": "b1508db6d12665823334dae974ecda979c183e6449a412871d87ae9f570a7339", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/15/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/15/performance-tips.html#USING-EXPLAIN\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "15", "link_map": {"/zh/docs/15/sql-explain.html": "/docs/15/sql-explain.html", "/zh/docs/15/performance-tips.html#USING-EXPLAIN": "/docs/15/performance-tips.html#USING-EXPLAIN"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/15/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/15/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "4b2d72c039e5cd55be70ee0dccbb41a0ccf1926e0cb9c8b17cf94765194d9133", "content_hash": "169911280b1708d5b6491d9835b093dc6518ae3402ba549feed3876fcd012e79", "source_database": "center", "source_revision": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/15/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/15/facts/3/label": "Output", "/versions/15/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/15/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/15/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/15/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/15/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/15/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "815d6d33b446d0d068a975da061293e35ec0e2256c172780d7f030029d7a0c78", "canonical_center_text_hash": "169911280b1708d5b6491d9835b093dc6518ae3402ba549feed3876fcd012e79"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/15/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/15/performance-tips.html#USING-EXPLAIN\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "16": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "a0541aa1274499034986a4359437b980870ab57e8522c1017b45447d4b212a68", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 1208, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1208", "sha256": "8e017f0116dbea471339b40c37a667cc9f95039e7e0329c783e5e8ce194de7e1", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "line": 171, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:171", "sha256": "e48c08e555f8cb4e4bb43df516c4b8906ce9bc374b2a745d98a1fc8c22cc5099", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/backend/executor/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "a0541aa1274499034986a4359437b980870ab57e8522c1017b45447d4b212a68", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "97db47353db76326b874589a5ad0a04501cc74cd72e237e7bd956e7472c41f1f", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/16/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "16", "build_id": 103, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "394de9d6895c7909a1a823408b8c980c5415db8ca3c212e23d6e7e9b6e01c6cc", "fragment_sha256": "8a4cc7ad0a2c8ca5894434db8a1fca93a69bfb200ac510843c26d7bd42a12d58", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:80579a071736780f9c4022bb5148e1fb1256f1a33591306af67816e9e9bf3a9b", "translated_from_revision": null}, "body_sha256": "ef4260afc237161f115740abd9400cb1cdd342c201cc57e758d011267950928a", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_ProjectSet", "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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", 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"T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/16/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "16", "build_id": 103, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "394de9d6895c7909a1a823408b8c980c5415db8ca3c212e23d6e7e9b6e01c6cc", "fragment_sha256": "8a4cc7ad0a2c8ca5894434db8a1fca93a69bfb200ac510843c26d7bd42a12d58", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:80579a071736780f9c4022bb5148e1fb1256f1a33591306af67816e9e9bf3a9b", "translated_from_revision": null}, "body_sha256": "ef4260afc237161f115740abd9400cb1cdd342c201cc57e758d011267950928a", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/16/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/16/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "16", "link_map": {"/zh/docs/16/sql-explain.html": "/docs/16/sql-explain.html", "/zh/docs/16/using-explain.html": "/docs/16/using-explain.html"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/16/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/16/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "35800c736bb47f19423b790c7ff15e21f75af8731b3995ae01dd8a28b967361e", "content_hash": "e54e25720f436957f6bbca63021bcc09d30f9eddf80353c46da2286e44b04c20", "source_database": "center", "source_revision": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/16/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/16/facts/3/label": "Output", "/versions/16/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/16/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/16/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/16/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/16/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/16/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "63f69e344904991f84432c3c1da8fa79ce72d7db8af558ae08269e787e4530d1", "canonical_center_text_hash": "e54e25720f436957f6bbca63021bcc09d30f9eddf80353c46da2286e44b04c20"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/16/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f 9.3 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/16/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "17": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "cf629c44c0d6012237736b31a33d0b3b3b08804b82661600ecd77a0966d00c99", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 1397, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1397", "sha256": "741251b1a3b6d269a52a673d42eb63b02e13a5872db7b359b137086ab21b63c8", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "line": 171, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:171", "sha256": "a77576e158b94cb01fa8c5174ba133004eabdd727660323f8afc66c8d2e757b8", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/backend/executor/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "cf629c44c0d6012237736b31a33d0b3b3b08804b82661600ecd77a0966d00c99", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "d390dd69e2d3f5085beb42b33e46ff0676a2959b916a12b82118a7e545f8e562", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/17/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "17", "build_id": 105, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "b1252952c6d796f5e38c223b74ff667f2d19d677dcf85fe5269b782b830e5013", "fragment_sha256": "8f5243c368dfae57e826af49b7461d37d7f4d97207bd5f540aebe6b10a61f883", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:7340767258d21c21b36f373f1fff6bab2be18e0daca13a865129db6105c09efd", "translated_from_revision": null}, "body_sha256": "e4ebb71c33dc40a3ef8b2bcd38f7e9c050f503e54891ebc40a760e3b84deeb93", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "facts_zh": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "node_tag": "T_ProjectSet", "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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "17", "text_hash": "1006309b19d30a8aebc1f9cf72e9ea702b49d7e7fbac720e04b4d3722ab3ad8f", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/17/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "17", "build_id": 105, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "b1252952c6d796f5e38c223b74ff667f2d19d677dcf85fe5269b782b830e5013", "fragment_sha256": "8f5243c368dfae57e826af49b7461d37d7f4d97207bd5f540aebe6b10a61f883", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:7340767258d21c21b36f373f1fff6bab2be18e0daca13a865129db6105c09efd", "translated_from_revision": null}, "body_sha256": "e4ebb71c33dc40a3ef8b2bcd38f7e9c050f503e54891ebc40a760e3b84deeb93", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/17/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v17 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/17/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "17", "link_map": {"/zh/docs/17/sql-explain.html": "/docs/17/sql-explain.html", "/zh/docs/17/using-explain.html": "/docs/17/using-explain.html"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/17/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v17 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/17/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "dffd59608a8230926527838f75ac7a911ff7a1f9007d4e75f8b48e0c0d8eee47", "content_hash": "1006309b19d30a8aebc1f9cf72e9ea702b49d7e7fbac720e04b4d3722ab3ad8f", "source_database": "center", "source_revision": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/17/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/17/facts/3/label": "Output", "/versions/17/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/17/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/17/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/17/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/17/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/17/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "de4c644c2ffcc939bd3b2fe07e099c840a8cd3636fe024cb903af80437ac2d04", "canonical_center_text_hash": "1006309b19d30a8aebc1f9cf72e9ea702b49d7e7fbac720e04b4d3722ab3ad8f"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/17/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v17 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/17/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "18": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "86da5522860678066d56fcdc7fabd9b4dc96aac818665f3d3b039df5805a0595", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 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"T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/18/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "18", "build_id": 107, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "d2f749744b3ac5aa2eb0154f295e8163903cd20fcc130c74c6172cdf2ae3a9df", "fragment_sha256": "15fbdf84b8f499253ade4f4a5841de138619a9933b93cc241d431dbe922fa40c", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b", "translated_from_revision": null}, "body_sha256": "db9cc09d47dd3ed342707f9698a03f7fc9177d56949a77439320e3489093ee3f", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/18/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "18", "link_map": {"/zh/docs/18/sql-explain.html": "/docs/18/sql-explain.html", "/zh/docs/18/using-explain.html": "/docs/18/using-explain.html"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "9bb00722e603ff6c73aef559d70b9f31e13aed36358b9607bfd7f928ba76012f", "content_hash": "143cbdc67220125a88875b37f8736400d8fbf6d13c0c57bf62af0fe62f112a73", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/18/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/18/facts/3/label": "Output", "/versions/18/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/18/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/18/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/18/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/18/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/18/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "e2aa64ebcf0cee5c0b0273f219f9d4afa7a9154a201e38925099222a50c8343f", "canonical_center_text_hash": "143cbdc67220125a88875b37f8736400d8fbf6d13c0c57bf62af0fe62f112a73"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "center_zh_rendered": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/docs/18/sql-explain.html\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "19": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"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/nodeProjectSet.c", "label": "src/backend/executor/nodeProjectSet.c", "sha256": "d0e9fd50ff795af486df76b9559593329fcce39ffc95ab9acbde1e72f23f0b6e", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=19", "label": "EXPLAIN"}, {"url": "/docs/19/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/19/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 19rc1 source archive", "label": "19rc1", "major": "19", "channel": "preview", "revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701", "source_url": "https://ftp.postgresql.org/pub/source/v19rc1/postgresql-19rc1.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": 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"node_tag": "T_ProjectSet", "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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "19", "text_hash": "ca23bd6f120ce4bc0f656ddda296c3e85bdfd9b29166cf43cb287c1a5a7f9d53", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/19/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "19", "build_id": 109, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "9bbb1ef5924e4788a3dc2642828383c67ab8651fb6b0e45924c454f095b0ff47", "fragment_sha256": "1ceb32499da15c4bcec0644765b693adbc1991296745e00460ce28d06d701ef3", "source_revision": "sha256:af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:65fda1f1b62a89992b84014c9157e61b67dbe8190e93945826efec668fad038c", "translated_from_revision": "sha256:af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "body_sha256": "a5be5f0cb0064c4818e0c976a90391a393f9ea5128afad097bfcb423c9991387", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/19/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/19/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "19", "link_map": {"/zh/docs/19/sql-explain.html": "/docs/19/sql-explain.html", "/zh/docs/19/using-explain.html": "/docs/19/using-explain.html"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/19/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/19/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "946dfc03b548dac3a71e132fd39542fe0533d0eb8c4b1c6d274aa051e4ca96d8", "content_hash": "ca23bd6f120ce4bc0f656ddda296c3e85bdfd9b29166cf43cb287c1a5a7f9d53", "source_database": "center", "source_revision": "af105fc8e960fc836a09fc2cd7f582b49fd17675d9d36631abe3a565bfd7d701"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/19/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/19/facts/3/label": "Output", "/versions/19/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/19/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/19/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/19/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/19/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/19/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). 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"manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN 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ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> 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["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "20", "text_hash": "1a380c255c663e1e15d4ac913d835580cce9eb96e20573abe5bd10dbcd3f67ef", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/devel/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "20", "build_id": 111, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "436517563e51b6d851ef143e70d01f5f68fe0a01e00a0d507e7bd79d7570aa25", "fragment_sha256": "f2d2c226e0479b8d931accead1f2cf7c1b8646afa24d8025ea5d5bcab837f779", "source_revision": "sha256:49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:98c980963b401d40bd50df72b909e7523e3148b8fdb48edd897de2efb67e5235", "translated_from_revision": "sha256:49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "body_sha256": "d446c327ddb83c4e60cce81443356f90a6fc3da3877e2f4b5d4a301502820eee", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/devel/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/devel/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "20", "link_map": {"/zh/docs/devel/sql-explain.html": "/docs/devel/sql-explain.html", "/zh/docs/devel/using-explain.html": "/docs/devel/using-explain.html"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/devel/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/devel/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "718d82c7c830c04093f855491e7a5d724d3eb892c04cf37f95c8cd5c2cb90b5f", "content_hash": "1a380c255c663e1e15d4ac913d835580cce9eb96e20573abe5bd10dbcd3f67ef", "source_database": "center", "source_revision": "49c73aa4c9cacef8ca979276a28ac416c08e9e54c9baee4ae5fd116a35fa13ac"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/summary": "Evaluates set-returning expressions in the target list for rows from its child.", "/category": "Control", "/versions/20/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/20/facts/3/label": "Output", "/versions/20/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/20/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/20/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/20/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/20/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/20/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "14a455872caf75343756f3ebcf57a6fd878dd1a1e038e0d0a06490387c3a5414", "canonical_center_text_hash": "1a380c255c663e1e15d4ac913d835580cce9eb96e20573abe5bd10dbcd3f67ef"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/devel/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/devel/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "source_revalidation": {"kind": "static-same-version-source-and-manual-replay", "audit": "wiki-audit-20261023", "runtime_rerun": false, "compared_fields": "entity membership and source-derived facts; presentation markup normalized", "source_revision": 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"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "mechanism": "unclassified", "description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "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": 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\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\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "center_zh": {"title": "ProjectSet", "locale": "zh-Hans", "source": {"key": "projectset", "locale": "zh-Hans", "version": "18", "text_hash": "143cbdc67220125a88875b37f8736400d8fbf6d13c0c57bf62af0fe62f112a73", "collection": "plan", "dataset_hash": "7c31b524dfe136022d39a6ae8dcfac6b3bbd5f8fdaf422536599981252aff0c9", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "payload": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_ProjectSet"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "ProjectSet"}, {"label": "\u8f93\u5165", "value": "\u4e00\u4e2a\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5c55\u5f00\u540e\u7684\u7ed3\u679c\u5143\u7ec4"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitProjectSet"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "tables": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "zh_from": {"kind": "same-version-chinese-manual-with-authored-translation-of-reviewed-guidance", "manual": {"url": "/zh/docs/18/using-explain.html", "anchor": "", "locale": "zh-Hans", "version": "18", "build_id": 107, "page_key": "using-explain.html", "extraction": "concept-introduction", "source_hash": "d2f749744b3ac5aa2eb0154f295e8163903cd20fcc130c74c6172cdf2ae3a9df", "fragment_sha256": "15fbdf84b8f499253ade4f4a5841de138619a9933b93cc241d431dbe922fa40c", "source_revision": "unknown:rendered-translation-baseline", "translation_revision": "git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b", "translated_from_revision": null}, "body_sha256": "db9cc09d47dd3ed342707f9698a03f7fc9177d56949a77439320e3489093ee3f", "runtime_rerun": false, "authored_translation": "authored-translation-of-reviewed-guidance", "source_facts_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span class=\"productname\">PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em class=\"firstterm\">\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em class=\"firstterm\">\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a class=\"link\" href=\"/zh/docs/18/sql-explain.html\"><code class=\"command\">EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code class=\"command\">VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code class=\"command\">ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code class=\"command\">EXPLAIN</code> \u9ed8\u8ba4\u7684<span class=\"quote\">\u201c<span class=\"quote\">text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code class=\"command\">EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "summary": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "version": "18", "link_map": {"/zh/docs/18/sql-explain.html": "/docs/18/sql-explain.html", "/zh/docs/18/using-explain.html": "/docs/18/using-explain.html"}, "body_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "body_sha256": "9bb00722e603ff6c73aef559d70b9f31e13aed36358b9607bfd7f928ba76012f", "content_hash": "143cbdc67220125a88875b37f8736400d8fbf6d13c0c57bf62af0fe62f112a73", "source_database": "center", "source_revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, "tables_zh": [{"key": "explain-labels", "rows": [{"label": "ProjectSet", "identity": "ProjectSet"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "strategies": [], "description": ["\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002"], "sections_zh": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aProjectSet.", "\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\uff1anone extracted from this node implementation."]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["nodeProjectSet.c\uff1a\u652f\u6301\u6c42\u503c\u542b\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u3002", "\u89c4\u5212\u5668\u63d2\u5165 ProjectSet \u8282\u70b9\u6765\u6c42\u503c\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u3002\u4fdd\u8bc1\u6240\u6709\u8fd9\u7c7b\u51fd\u6570\u76f4\u63a5\u4f4d\u4e8e\u76ee\u6807\u5217\u8868\u9876\u5c42\uff0c\u800c\u975e\u5d4c\u5728\u66f4\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u5185\u90e8\uff1b\u82e5\u539f\u672c\u5b58\u5728\u8fd9\u79cd\u5d4c\u5957\uff0c\u89c4\u5212\u5668\u4f1a\u6dfb\u52a0\u989d\u5916\u7684 ProjectSet \u8282\u70b9\u3002", "\u6c42\u503c\u542b\u6709\u96c6\u5408\u8fd4\u56de\u51fd\u6570\u7684\u76ee\u6807\u5217\u8868\u540e\uff0c\u8fd4\u56de\u5143\u7ec4\u3002", "\u91cd\u7f6e\u9010\u5143\u7ec4\u4e0a\u4e0b\u6587\uff0c\u91ca\u653e\u53ef\u80fd\u4e3a\u4e0a\u4e00\u4e2a\u8fd4\u56de\u5143\u7ec4\u5206\u914d\u7684\u8868\u8fbe\u5f0f\u6c42\u503c\u5b58\u50a8\u3002SRF \u53c2\u6570\u4e0a\u4e0b\u6587\u7684\u751f\u547d\u5468\u671f\u4e0d\u540c\uff0c\u5c06\u5728\u4e0b\u6587\u91cd\u7f6e\u3002", "\u68c0\u67e5\u662f\u5426\u4ecd\u5728\u4ece\u4e0a\u4e00\u4e2a\u626b\u63cf\u5143\u7ec4\u6295\u5f71\u8f93\u51fa\u5143\u7ec4\uff08\u56e0\u4e3a\u6295\u5f71\u8868\u8fbe\u5f0f\u4e2d\u5305\u542b\u8fd4\u56de\u96c6\u5408\u7684\u51fd\u6570\uff09\u3002\u5982\u679c\u662f\uff0c\u5c1d\u8bd5\u518d\u6295\u5f71\u4e00\u4e2a\u5143\u7ec4\u3002"]}, {"code": "case T_ProjectSet:\n\t\t\tpname = sname = \"ProjectSet\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/18/description/0": "Evaluates set-returning expressions in the target list for rows from its child.", "/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": "One child plan", "/versions/18/facts/3/label": "Output", "/versions/18/facts/3/value": "Expanded result 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: ProjectSet.", "/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: none extracted from this node implementation.", "/versions/18/sections/3/paragraphs/0": "nodeProjectSet.c support for evaluating targetlists containing set-returning functions", "/versions/18/sections/3/paragraphs/1": "ProjectSet nodes are inserted by the planner to evaluate set-returning functions in the targetlist. It's guaranteed that all set-returning functions are directly at the top level of the targetlist, i.e. they can't be inside more-complex expressions. If that'd otherwise be the case, the planner adds additional ProjectSet nodes.", "/versions/18/sections/3/paragraphs/2": "Return tuples after evaluating the targetlist (which contains set returning functions).", "/versions/18/sections/3/paragraphs/3": "Reset per-tuple context to free expression-evaluation storage allocated for a potentially previously returned tuple. Note that the SRF argument context has a different lifetime and is reset below.", "/versions/18/sections/3/paragraphs/4": "Check to see if we're still projecting out tuples from a previous scan tuple (because there is a function-returning-set in the projection expressions). If so, try to project another one.", "/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": "e2aa64ebcf0cee5c0b0273f219f9d4afa7a9154a201e38925099222a50c8343f", "canonical_center_text_hash": "143cbdc67220125a88875b37f8736400d8fbf6d13c0c57bf62af0fe62f112a73"}, "evidence_kind": "source and documentation", "explain_names": ["ProjectSet"], "partial_modes": [], "description_zh": "\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002", "comparison_data": {"node_tag": "T_ProjectSet", "strategies": [], "text_names": ["ProjectSet"], "initializer": "ExecInitProjectSet", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "67eb48dae4edf18acce1d9762e9a041057c4b07a8b1b127ee6f4a2bca7960ed8", "manual_language": "zh", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeProjectSet.c"}, "parallel_callbacks": [], "description_zh_html": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/zh/docs/18/sql-explain.html\" rel=\"nofollow\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/zh/docs/18/using-explain.html\" rel=\"nofollow\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>", "center_zh_rendered": "<p>\u5bf9\u6765\u81ea\u5b50\u8ba1\u5212\u7684\u6bcf\u4e00\u884c\u8ba1\u7b97\u76ee\u6807\u5217\u8868\u4e2d\u7684\u96c6\u5408\u8fd4\u56de\u8868\u8fbe\u5f0f\u3002</p><p>\u6838\u5fc3\u8282\u70b9\u6807\u8bc6\uff1a<code>T_ProjectSet</code>\uff1bEXPLAIN \u540d\u79f0\uff1a<code>ProjectSet</code>\u3002</p><p>\u672c\u7248\u672c\u6e90\u7801\u4e2d\u7684\u5e76\u884c\u6267\u884c\u6216\u89c2\u6d4b\u56de\u8c03\uff1a\u8be5\u8282\u70b9\u5b9e\u73b0\u4e2d\u672a\u63d0\u53d6\u5230\u6b64\u7c7b\u56de\u8c03\u3002\u56de\u8c03\u7684\u5b58\u5728\u4e0d\u8868\u793a\u8be5\u8282\u70b9\u5fc5\u7136\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\uff1b\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u4e2d\u6267\u884c\u4e5f\u4e0d\u7b49\u4e8e\u5177\u6709\u5e76\u884c\u611f\u77e5\u80fd\u529b\u3002</p><h3>\u540c\u7248\u672c\u4e2d\u6587\u624b\u518c\u8282\u9009</h3><p>\n<span>PostgreSQL</span> \u4f1a\u4e3a\u6536\u5230\u7684\u6bcf\u4e2a\u67e5\u8be2\u5236\u5b9a\u4e00\u4e2a<em>\u67e5\u8be2\u8ba1\u5212</em>\u3002\u9009\u62e9\u4e0e\u67e5\u8be2\u7ed3\u6784\u548c\u6570\u636e\u7279\u6027\u76f8\u5339\u914d\u7684\u6b63\u786e\u8ba1\u5212\uff0c\u5bf9\u83b7\u5f97\u826f\u597d\u7684\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u6b64\u7cfb\u7edf\u5185\u7f6e\u4e86\u4e00\u4e2a\u590d\u6742\u7684<em>\u89c4\u5212\u5668</em>\u6765\u5c3d\u91cf\u9009\u51fa\u597d\u7684\u8ba1\u5212\u3002\u53ef\u4ee5\u4f7f\u7528 <a href=\"/docs/18/sql-explain.html\"><code>EXPLAIN</code></a> \u547d\u4ee4\u67e5\u770b\u89c4\u5212\u5668\u4e3a\u4efb\u610f\u67e5\u8be2\u751f\u6210\u7684\u67e5\u8be2\u8ba1\u5212\u3002\u8bfb\u61c2\u8ba1\u5212\u662f\u4e00\u95e8\u9700\u8981\u7ecf\u9a8c\u79ef\u7d2f\u7684\u6280\u80fd\uff0c\u672c\u8282\u5c06\u5c1d\u8bd5\u4ecb\u7ecd\u5176\u4e2d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\n   </p><p>\n    \u672c\u8282\u4e2d\u7684\u793a\u4f8b\u53d6\u81ea\u6267\u884c\u8fc7 <code>VACUUM ANALYZE</code> \u7684\u56de\u5f52\u6d4b\u8bd5\u6570\u636e\u5e93\uff0c\u4f7f\u7528\u7684\u662f v18 \u5f00\u53d1\u7248\u672c\u6e90\u7801\u3002\u5982\u679c\u81ea\u884c\u5c1d\u8bd5\u8fd9\u4e9b\u793a\u4f8b\uff0c\u901a\u5e38\u5e94\u5f53\u80fd\u5f97\u5230\u76f8\u8fd1\u7684\u7ed3\u679c\uff0c\u4f46\u4f30\u8ba1\u4ee3\u4ef7\u548c\u884c\u8ba1\u6570\u53ef\u80fd\u7565\u6709\u5dee\u5f02\uff0c\u56e0\u4e3a <code>ANALYZE</code> \u751f\u6210\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u81ea\u968f\u673a\u91c7\u6837\u800c\u975e\u7cbe\u786e\u8ba1\u6570\uff0c\u800c\u4e14\u4ee3\u4ef7\u672c\u8eab\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u4e5f\u4f9d\u8d56\u4e8e\u5e73\u53f0\u3002\n   </p><p>\n    \u8fd9\u4e9b\u793a\u4f8b\u4f7f\u7528 <code>EXPLAIN</code> \u9ed8\u8ba4\u7684<span>\u201c<span>text</span>\u201d</span>\u8f93\u51fa\u683c\u5f0f\uff0c\u5b83\u7d27\u51d1\u4e14\u4fbf\u4e8e\u4eba\u5de5\u9605\u8bfb\u3002\u5982\u679c\u5e0c\u671b\u5c06 <code>EXPLAIN</code> \u7684\u8f93\u51fa\u4ea4\u7ed9\u7a0b\u5e8f\u505a\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u5219\u5e94\u6539\u7528\u673a\u5668\u53ef\u8bfb\u7684\u8f93\u51fa\u683c\u5f0f\uff08XML\u3001JSON \u6216 YAML\uff09\u3002\n   </p><p><a href=\"/docs/18/using-explain.html\">\u67e5\u770b\u5b8c\u6574\u4e2d\u6587\u624b\u518c\u4e0e\u4e0a\u4e0b\u6587</a>\u3002</p><p>\u672c\u9875\u5f00\u5934\u7684\u4e2d\u6587\u8bf4\u660e\u4e3a PG.CENTER \u5bf9\u7f16\u8f91\u8bf4\u660e\u7684\u7ffb\u8bd1\uff1b\u624b\u518c\u8282\u9009\u4fdd\u7559\u5bf9\u5e94\u7248\u672c\u4e2d\u6587\u6587\u6863\u539f\u6587\u3002\u6e90\u7801\u4fe1\u606f\u53ca\u624b\u518c\u793a\u4f8b\u4e0d\u4ee3\u8868\u91cd\u65b0\u8fdb\u884c\u8fc7\u8fd0\u884c\u6d4b\u8bd5\u3002</p>"}, "comparison": {"left": "17", "right": "18", "status": "unchanged", "diff": ""}}