{"id":93916,"date":"2024-10-19T17:59:17","date_gmt":"2024-10-19T09:59:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/93916\/"},"modified":"2024-10-19T17:59:18","modified_gmt":"2024-10-19T09:59:18","slug":"oracle-explain-plan%e7%9a%84%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8%e7%b6%93%e9%a9%97%e7%b8%bd%e7%b5%90","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/93916\/","title":{"rendered":"Oracle EXPLAIN PLAN\u7684\u5be6\u969b\u61c9\u7528\u7d93\u9a57\u7e3d\u7d50"},"content":{"rendered":"<h1 id=\"oracle-explain-plan%e7%9a%84%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8%e7%b6%93%e9%a9%97%e7%b8%bd%e7%b5%90-ShydfCRPLM\">Oracle EXPLAIN PLAN\u7684\u5be6\u969b\u61c9\u7528\u7d93\u9a57\u7e3d\u7d50<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u6027\u80fd\u512a\u5316\u662f\u78ba\u4fdd\u61c9\u7528\u7a0b\u5e8f\u9ad8\u6548\u904b\u884c\u7684\u95dc\u9375\u3002Oracle\u6578\u64da\u5eab\u63d0\u4f9b\u4e86\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\u2014\u2014EXPLAIN PLAN\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u5206\u6790SQL\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u672c\u6587\u5c07\u63a2\u8a0eEXPLAIN PLAN\u7684\u5be6\u969b\u61c9\u7528\u7d93\u9a57\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u6700\u4f73\u5be6\u8e10\u548c\u793a\u4f8b\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afexplain-plan%ef%bc%9f-ShydfCRPLM\">\u4ec0\u9ebc\u662fEXPLAIN PLAN\uff1f<\/h2>\n<p>EXPLAIN PLAN\u662f\u4e00\u500bOracle\u6578\u64da\u5eab\u547d\u4ee4\uff0c\u7528\u65bc\u986f\u793aSQL\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u9019\u500b\u8a08\u5283\u63cf\u8ff0\u4e86\u6578\u64da\u5eab\u5982\u4f55\u57f7\u884c\u67e5\u8a62\uff0c\u5305\u62ec\u4f7f\u7528\u7684\u7d22\u5f15\u3001\u8868\u7684\u8a2a\u554f\u9806\u5e8f\u4ee5\u53ca\u5176\u4ed6\u57f7\u884c\u7d30\u7bc0\u3002\u901a\u904e\u5206\u6790\u9019\u4e9b\u4fe1\u606f\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8b58\u5225\u6f5b\u5728\u7684\u6027\u80fd\u74f6\u9838\uff0c\u4e26\u9032\u884c\u76f8\u61c9\u7684\u512a\u5316\u3002<\/p>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8explain-plan-ShydfCRPLM\">\u5982\u4f55\u4f7f\u7528EXPLAIN PLAN<\/h2>\n<p>\u4f7f\u7528EXPLAIN PLAN\u975e\u5e38\u7c21\u55ae\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u57fa\u672c\u7684\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n<pre><code>EXPLAIN PLAN FOR\nSELECT * FROM employees WHERE department_id = 10;<\/code><\/pre>\n<p>\u57f7\u884c\u4e0a\u8ff0\u547d\u4ee4\u5f8c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\u4f86\u67e5\u770b\u57f7\u884c\u8a08\u5283\uff1a<\/p>\n<pre><code>SELECT * FROM table(DBMS_XPLAN.DISPLAY());<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de\u4e00\u500b\u8868\u683c\uff0c\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5305\u62ec\u6bcf\u500b\u6b65\u9a5f\u7684\u6210\u672c\u3001\u884c\u6578\u548c\u5176\u4ed6\u76f8\u95dc\u4fe1\u606f\u3002<\/p>\n<h2 id=\"explain-plan%e7%9a%84%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8%e7%b6%93%e9%a9%97-ShydfCRPLM\">EXPLAIN PLAN\u7684\u5be6\u969b\u61c9\u7528\u7d93\u9a57<\/h2>\n<h3 id=\"1-%e7%a2%ba%e5%ae%9a%e6%80%a7%e8%83%bd%e7%93%b6%e9%a0%b8-ShydfCRPLM\">1. \u78ba\u5b9a\u6027\u80fd\u74f6\u9838<\/h3>\n<p>\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0cEXPLAIN PLAN\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5feb\u901f\u5b9a\u4f4d\u6027\u80fd\u74f6\u9838\u3002\u4f8b\u5982\uff0c\u7576\u4e00\u500b\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\u904e\u9577\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528EXPLAIN PLAN\u4f86\u6aa2\u67e5\u662f\u5426\u4f7f\u7528\u4e86\u9069\u7576\u7684\u7d22\u5f15\u3002\u5982\u679c\u767c\u73fe\u67e5\u8a62\u4f7f\u7528\u5168\u8868\u6383\u63cf\u800c\u4e0d\u662f\u7d22\u5f15\u6383\u63cf\uff0c\u5247\u53ef\u4ee5\u8003\u616e\u5275\u5efa\u7d22\u5f15\u4f86\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n<h3 id=\"2-%e6%af%94%e8%bc%83%e4%b8%8d%e5%90%8c%e6%9f%a5%e8%a9%a2%e7%9a%84%e5%9f%b7%e8%a1%8c%e8%a8%88%e5%8a%83-ShydfCRPLM\">2. \u6bd4\u8f03\u4e0d\u540c\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283<\/h3>\n<p>\u5728\u512a\u5316\u67e5\u8a62\u6642\uff0c\u958b\u767c\u8005\u7d93\u5e38\u9700\u8981\u6bd4\u8f03\u4e0d\u540c\u7248\u672c\u7684SQL\u67e5\u8a62\u3002\u4f7f\u7528EXPLAIN PLAN\uff0c\u53ef\u4ee5\u8f15\u9b06\u5730\u7372\u53d6\u6bcf\u500b\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u4e26\u9032\u884c\u6bd4\u8f03\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>EXPLAIN PLAN FOR\nSELECT * FROM employees WHERE last_name = 'Smith';\n\nEXPLAIN PLAN FOR\nSELECT * FROM employees WHERE UPPER(last_name) = 'SMITH';<\/code><\/pre>\n<p>\u901a\u904e\u6bd4\u8f03\u9019\u5169\u500b\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u4e86\u89e3\u54ea\u500b\u67e5\u8a62\u66f4\u6709\u6548\uff0c\u4e26\u6839\u64da\u9700\u8981\u9032\u884c\u8abf\u6574\u3002<\/p>\n<h3 id=\"3-%e7%9b%a3%e6%8e%a7%e6%9f%a5%e8%a9%a2%e6%80%a7%e8%83%bd%e8%ae%8a%e5%8c%96-ShydfCRPLM\">3. \u76e3\u63a7\u67e5\u8a62\u6027\u80fd\u8b8a\u5316<\/h3>\n<p>\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u67e5\u8a62\u7684\u6027\u80fd\u53ef\u80fd\u6703\u767c\u751f\u8b8a\u5316\u3002\u5b9a\u671f\u4f7f\u7528EXPLAIN PLAN\u4f86\u76e3\u63a7\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u53ca\u6642\u767c\u73fe\u6027\u80fd\u4e0b\u964d\u7684\u554f\u984c\u3002\u4f8b\u5982\uff0c\u7576\u65b0\u6578\u64da\u88ab\u63d2\u5165\u5230\u8868\u4e2d\u6642\uff0c\u539f\u672c\u6709\u6548\u7684\u67e5\u8a62\u53ef\u80fd\u6703\u8b8a\u5f97\u7de9\u6162\u3002\u901a\u904eEXPLAIN PLAN\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u6aa2\u67e5\u57f7\u884c\u8a08\u5283\u7684\u8b8a\u5316\uff0c\u4e26\u9032\u884c\u76f8\u61c9\u7684\u512a\u5316\u3002<\/p>\n<h2 id=\"%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-ShydfCRPLM\">\u6700\u4f73\u5be6\u8e10<\/h2>\n<ul>\n<li>\u5b9a\u671f\u4f7f\u7528EXPLAIN PLAN\u4f86\u6aa2\u67e5\u95dc\u9375\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002<\/li>\n<li>\u5728\u9032\u884c\u67e5\u8a62\u512a\u5316\u6642\uff0c\u8a18\u9304\u6bcf\u500b\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u4ee5\u4fbf\u9032\u884c\u6bd4\u8f03\u3002<\/li>\n<li>\u7d50\u5408\u4f7f\u7528\u5176\u4ed6\u6027\u80fd\u76e3\u63a7\u5de5\u5177\uff0c\u4ee5\u7372\u53d6\u66f4\u5168\u9762\u7684\u6027\u80fd\u5206\u6790\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-ShydfCRPLM\">\u7e3d\u7d50<\/h2>\n<p>Oracle\u7684EXPLAIN PLAN\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u5206\u6790\u548c\u512a\u5316SQL\u67e5\u8a62\u7684\u6027\u80fd\u3002\u901a\u904e\u5b9a\u671f\u4f7f\u7528EXPLAIN PLAN\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u53ca\u6642\u767c\u73fe\u6027\u80fd\u74f6\u9838\uff0c\u4e26\u9032\u884c\u76f8\u61c9\u7684\u512a\u5316\u3002\u9019\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u7684\u57f7\u884c\u6548\u7387\uff0c\u9084\u80fd\u6539\u5584\u6574\u9ad4\u7cfb\u7d71\u7684\u6027\u80fd\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\u4f86\u8aaa\uff0c\u638c\u63e1EXPLAIN PLAN\u7684\u4f7f\u7528\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u53ef\u9760\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Oracle EXPLAIN PLAN\u7684\u5be6\u969b\u61c9\u7528\u7d93\u9a57\uff0c\u63d0\u5347\u67e5\u8a62\u6027\u80fd\uff0c\u512a\u5316\u6578\u64da\u5eab\u6548\u7387\uff0c\u5be6\u73fe\u66f4\u5feb\u7684\u6578\u64da\u8655\u7406\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-93916","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/93916","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=93916"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/93916\/revisions"}],"predecessor-version":[{"id":93917,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/93916\/revisions\/93917"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=93916"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=93916"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=93916"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}