{"id":96186,"date":"2024-10-20T07:19:17","date_gmt":"2024-10-19T23:19:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96186\/"},"modified":"2024-10-20T07:19:18","modified_gmt":"2024-10-19T23:19:18","slug":"oracle%e7%94%a8explain-plan%e5%88%86%e6%9e%90sql%e8%aa%9e%e5%8f%a5%e7%9a%84%e5%af%a6%e4%be%8b%e8%a7%a3%e6%9e%90","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96186\/","title":{"rendered":"Oracle\u7528EXPLAIN PLAN\u5206\u6790SQL\u8a9e\u53e5\u7684\u5be6\u4f8b\u89e3\u6790"},"content":{"rendered":"<h1 id=\"oracle%e7%94%a8explain-plan%e5%88%86%e6%9e%90sql%e8%aa%9e%e5%8f%a5%e7%9a%84%e5%af%a6%e4%be%8b%e8%a7%a3%e6%9e%90-pJAtiVBvBQ\">Oracle\u7528EXPLAIN PLAN\u5206\u6790SQL\u8a9e\u53e5\u7684\u5be6\u4f8b\u89e3\u6790<\/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\u7528\u6236\u5206\u6790SQL\u8a9e\u53e5\u7684\u57f7\u884c\u8a08\u5283\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u5982\u4f55\u4f7f\u7528EXPLAIN PLAN\u4f86\u5206\u6790SQL\u8a9e\u53e5\uff0c\u4e26\u901a\u904e\u5be6\u4f8b\u89e3\u6790\u5176\u904b\u4f5c\u539f\u7406\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afexplain-plan%ef%bc%9f-pJAtiVBvBQ\">\u4ec0\u9ebc\u662fEXPLAIN PLAN\uff1f<\/h2>\n<p>EXPLAIN PLAN\u662f\u4e00\u500bOracle\u6578\u64da\u5eab\u7684\u529f\u80fd\uff0c\u5141\u8a31\u7528\u6236\u67e5\u770bSQL\u8a9e\u53e5\u7684\u57f7\u884c\u8a08\u5283\u3002\u9019\u500b\u8a08\u5283\u986f\u793a\u4e86\u6578\u64da\u5eab\u5c07\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\u91cd\u8981\u7684\u57f7\u884c\u7d30\u7bc0\u3002\u901a\u904e\u5206\u6790\u9019\u4e9b\u4fe1\u606f\uff0c\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\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-pJAtiVBvBQ\">\u5982\u4f55\u4f7f\u7528EXPLAIN PLAN<\/h2>\n<p>\u4f7f\u7528EXPLAIN PLAN\u7684\u57fa\u672c\u6b65\u9a5f\u5982\u4e0b\uff1a<\/p>\n<ol>\n<li>\u9996\u5148\uff0c\u78ba\u4fdd\u4f60\u6709\u8db3\u5920\u7684\u6b0a\u9650\u4f86\u57f7\u884cEXPLAIN PLAN\u3002<\/li>\n<li>\u7136\u5f8c\uff0c\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\u4f86\u751f\u6210\u57f7\u884c\u8a08\u5283\uff1a<\/li>\n<\/ol>\n<pre><code>EXPLAIN PLAN FOR \nSELECT * FROM employees WHERE department_id = 10;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u751f\u6210\u4e00\u500b\u57f7\u884c\u8a08\u5283\uff0c\u8a72\u8a08\u5283\u5c07\u88ab\u5b58\u5132\u5728\u4e00\u500b\u540d\u70baPLAN_TABLE\u7684\u8868\u4e2d\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e7%9c%8b%e5%9f%b7%e8%a1%8c%e8%a8%88%e5%8a%83-pJAtiVBvBQ\">\u67e5\u770b\u57f7\u884c\u8a08\u5283<\/h2>\n<p>\u751f\u6210\u57f7\u884c\u8a08\u5283\u5f8c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\u4f86\u67e5\u770b\u8a08\u5283\u7684\u5167\u5bb9\uff1a<\/p>\n<pre><code>SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY());<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u986f\u793a\u6700\u8fd1\u751f\u6210\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5305\u62ec\u6bcf\u500b\u6b65\u9a5f\u7684\u8a73\u7d30\u4fe1\u606f\uff0c\u5982\u64cd\u4f5c\u985e\u578b\u3001\u6210\u672c\u548c\u884c\u6578\u7b49\u3002<\/p>\n<h2 id=\"%e5%af%a6%e4%be%8b%e8%a7%a3%e6%9e%90-pJAtiVBvBQ\">\u5be6\u4f8b\u89e3\u6790<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba\u201cemployees\u201d\u7684\u8868\uff0c\u4e26\u4e14\u6211\u5011\u60f3\u8981\u67e5\u8a62\u6240\u6709\u90e8\u9580ID\u70ba10\u7684\u54e1\u5de5\u3002\u9996\u5148\uff0c\u6211\u5011\u57f7\u884cEXPLAIN PLAN\uff1a<\/p>\n<pre><code>EXPLAIN PLAN FOR \nSELECT * FROM employees WHERE department_id = 10;<\/code><\/pre>\n<p>\u63a5\u4e0b\u4f86\uff0c\u6211\u5011\u67e5\u770b\u57f7\u884c\u8a08\u5283\uff1a<\/p>\n<pre><code>SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY());<\/code><\/pre>\n<p>\u57f7\u884c\u8a08\u5283\u7684\u8f38\u51fa\u53ef\u80fd\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre><code>Plan hash value: 1234567890\n\n--------------------------------------------------------------------------------\n| Id  | Operation          | Name       | Rows  | Bytes | Cost (%CPU)| Time     |\n--------------------------------------------------------------------------------\n|   0 | SELECT STATEMENT   |            |       |       |   10 (10)   | 00:00:01 |\n|   1 | TABLE ACCESS FULL  | EMPLOYEES  |   100 |  2000 |   10 (10)   | 00:00:01 |\n--------------------------------------------------------------------------------<\/code><\/pre>\n<p>\u5f9e\u9019\u500b\u8a08\u5283\u4e2d\uff0c\u6211\u5011\u53ef\u4ee5\u770b\u5230Oracle\u9078\u64c7\u4e86\u201cTABLE ACCESS FULL\u201d\u64cd\u4f5c\uff0c\u9019\u610f\u5473\u8457\u5b83\u5c07\u6383\u63cf\u6574\u500b\u201cemployees\u201d\u8868\u4f86\u67e5\u627e\u7b26\u5408\u689d\u4ef6\u7684\u884c\u3002\u9019\u7a2e\u65b9\u6cd5\u5728\u8868\u6578\u64da\u91cf\u8f03\u5c0f\u6642\u662f\u53ef\u884c\u7684\uff0c\u4f46\u5982\u679c\u8868\u7684\u6578\u64da\u91cf\u5f88\u5927\uff0c\u5247\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u554f\u984c\u3002<\/p>\n<h2 id=\"%e5%84%aa%e5%8c%96%e5%bb%ba%e8%ad%b0-pJAtiVBvBQ\">\u512a\u5316\u5efa\u8b70<\/h2>\n<p>\u6839\u64da\u4e0a\u8ff0\u57f7\u884c\u8a08\u5283\uff0c\u6211\u5011\u53ef\u4ee5\u8003\u616e\u4ee5\u4e0b\u512a\u5316\u63aa\u65bd\uff1a<\/p>\n<ul>\n<li>\u5275\u5efa\u7d22\u5f15\uff1a\u5982\u679c\u201cdepartment_id\u201d\u5217\u4e0a\u6709\u7d22\u5f15\uff0cOracle\u5c07\u80fd\u5920\u66f4\u5feb\u5730\u67e5\u627e\u7b26\u5408\u689d\u4ef6\u7684\u884c\uff0c\u5f9e\u800c\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002<\/li>\n<li>\u91cd\u69cb\u67e5\u8a62\uff1a\u6839\u64da\u696d\u52d9\u9700\u6c42\uff0c\u8003\u616e\u662f\u5426\u53ef\u4ee5\u91cd\u69cb\u67e5\u8a62\u4ee5\u6e1b\u5c11\u6578\u64da\u7684\u6aa2\u7d22\u91cf\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-pJAtiVBvBQ\">\u7e3d\u7d50<\/h2>\n<p>EXPLAIN PLAN\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\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\u7406\u89e3\u57f7\u884c\u8a08\u5283\u7684\u5167\u5bb9\uff0c\u4f7f\u7528\u8005\u53ef\u4ee5\u8b58\u5225\u6f5b\u5728\u7684\u6027\u80fd\u74f6\u9838\u4e26\u63a1\u53d6\u76f8\u61c9\u7684\u512a\u5316\u63aa\u65bd\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\u7a0b\u5e8f\uff0c\u638c\u63e1EXPLAIN PLAN\u7684\u4f7f\u7528\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528\u6211\u5011\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u670d\u52d9\uff0c\u70ba\u60a8\u7684\u61c9\u7528\u7a0b\u5e8f\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u89e3\u6790Oracle\u4e2dEXPLAIN PLAN\u7684\u4f7f\u7528\uff0c\u5e6b\u52a9\u7406\u89e3SQL\u8a9e\u53e5\u7684\u57f7\u884c\u8a08\u5283\u8207\u6027\u80fd\u512a\u5316\u6280\u5de7\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-96186","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96186","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=96186"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96186\/revisions"}],"predecessor-version":[{"id":96187,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96186\/revisions\/96187"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96186"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96186"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96186"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}