{"id":160129,"date":"2024-11-03T20:31:17","date_gmt":"2024-11-03T12:31:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160129\/"},"modified":"2024-11-03T20:31:19","modified_gmt":"2024-11-03T12:31:19","slug":"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-explain","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160129\/","title":{"rendered":"OceanBase \u6559\u7a0b\uff1aOceanBase EXPLAIN"},"content":{"rendered":"<h1 id=\"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-explain-hLDeLGqlSm\">OceanBase \u6559\u7a0b\uff1aOceanBase EXPLAIN<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u9a45\u52d5\u6642\u4ee3\uff0c\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u6548\u7387\u5c0d\u65bc\u4f01\u696d\u7684\u6210\u529f\u81f3\u95dc\u91cd\u8981\u3002OceanBase \u4f5c\u70ba\u4e00\u6b3e\u9ad8\u6027\u80fd\u7684\u5206\u4f48\u5f0f\u6578\u64da\u5eab\uff0c\u5df2\u7d93\u5728\u8a31\u591a\u5927\u578b\u4f01\u696d\u4e2d\u5f97\u5230\u4e86\u5ee3\u6cdb\u61c9\u7528\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e OceanBase \u7684 EXPLAIN \u8a9e\u53e5\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7406\u89e3\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5f9e\u800c\u512a\u5316\u6578\u64da\u5eab\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-oceanbase-explain%ef%bc%9f-hLDeLGqlSm\">\u4ec0\u9ebc\u662f OceanBase EXPLAIN\uff1f<\/h2>\n<p>EXPLAIN \u662f\u4e00\u500b\u7528\u65bc\u5206\u6790 SQL \u67e5\u8a62\u57f7\u884c\u8a08\u5283\u7684\u5de5\u5177\u3002\u901a\u904e\u4f7f\u7528 EXPLAIN \u8a9e\u53e5\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u7372\u53d6\u6709\u95dc\u67e5\u8a62\u5982\u4f55\u88ab\u57f7\u884c\u7684\u8a73\u7d30\u4fe1\u606f\uff0c\u5305\u62ec\u4f7f\u7528\u7684\u7d22\u5f15\u3001\u6578\u64da\u6383\u63cf\u7684\u65b9\u5f0f\u4ee5\u53ca\u9810\u8a08\u7684\u884c\u6578\u7b49\u3002\u9019\u4e9b\u4fe1\u606f\u5c0d\u65bc\u512a\u5316\u67e5\u8a62\u6027\u80fd\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-oceanbase-explain-hLDeLGqlSm\">\u5982\u4f55\u4f7f\u7528 OceanBase EXPLAIN<\/h2>\n<p>\u5728 OceanBase \u4e2d\uff0c\u4f7f\u7528 EXPLAIN \u8a9e\u53e5\u975e\u5e38\u7c21\u55ae\u3002\u57fa\u672c\u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>EXPLAIN SELECT * FROM table_name WHERE condition;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u8fd4\u56de\u4e00\u500b\u8868\u683c\uff0c\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684 EXPLAIN \u8f38\u51fa\u5b57\u6bb5\uff1a<\/p>\n<ul>\n<li><strong>id<\/strong>\uff1a\u67e5\u8a62\u7684\u552f\u4e00\u6a19\u8b58\u7b26\u3002<\/li>\n<li><strong>select_type<\/strong>\uff1a\u67e5\u8a62\u7684\u985e\u578b\uff0c\u4f8b\u5982\u7c21\u55ae\u67e5\u8a62\u6216\u806f\u5408\u67e5\u8a62\u3002<\/li>\n<li><strong>table<\/strong>\uff1a\u6d89\u53ca\u7684\u8868\u540d\u3002<\/li>\n<li><strong>type<\/strong>\uff1a\u806f\u63a5\u985e\u578b\uff0c\u986f\u793a\u67e5\u8a62\u7684\u6548\u7387\u3002<\/li>\n<li><strong>possible_keys<\/strong>\uff1a\u53ef\u80fd\u4f7f\u7528\u7684\u7d22\u5f15\u3002<\/li>\n<li><strong>key<\/strong>\uff1a\u5be6\u969b\u4f7f\u7528\u7684\u7d22\u5f15\u3002<\/li>\n<li><strong>rows<\/strong>\uff1a\u9810\u8a08\u6383\u63cf\u7684\u884c\u6578\u3002<\/li>\n<li><strong>Extra<\/strong>\uff1a\u5176\u4ed6\u4fe1\u606f\uff0c\u4f8b\u5982\u662f\u5426\u4f7f\u7528\u4e86\u81e8\u6642\u8868\u3002<\/li>\n<\/ul>\n<h2 id=\"explain-%e7%9a%84%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8-hLDeLGqlSm\">EXPLAIN \u7684\u5be6\u969b\u61c9\u7528<\/h2>\n<p>\u70ba\u4e86\u66f4\u597d\u5730\u7406\u89e3 EXPLAIN \u7684\u4f7f\u7528\uff0c\u4ee5\u4e0b\u662f\u4e00\u500b\u5177\u9ad4\u7684\u4f8b\u5b50\uff1a<\/p>\n<pre><code>EXPLAIN SELECT name, age FROM users WHERE age &gt; 30;<\/code><\/pre>\n<p>\u57f7\u884c\u9019\u689d\u8a9e\u53e5\u5f8c\uff0c\u60a8\u53ef\u80fd\u6703\u770b\u5230\u5982\u4e0b\u7684\u8f38\u51fa\uff1a<\/p>\n<pre><code>\n+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+\n| id | select_type | table | type  | possible_keys | key     | key_len | ref  | rows | Extra       |\n+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+\n|  1 | SIMPLE      | users | range | age_index     | age_index| 4       | NULL |  100 | Using where |\n+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u53ef\u4ee5\u770b\u5230\u67e5\u8a62\u4f7f\u7528\u4e86\u540d\u70ba <code>age_index<\/code> \u7684\u7d22\u5f15\uff0c\u4e26\u4e14\u9810\u8a08\u6383\u63cf\u7d04 100 \u884c\u6578\u64da\u3002\u9019\u4e9b\u4fe1\u606f\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5224\u65b7\u67e5\u8a62\u7684\u6548\u7387\uff0c\u4e26\u9032\u884c\u76f8\u61c9\u7684\u512a\u5316\u3002<\/p>\n<h2 id=\"%e5%84%aa%e5%8c%96%e6%9f%a5%e8%a9%a2%e6%80%a7%e8%83%bd%e7%9a%84%e5%bb%ba%e8%ad%b0-hLDeLGqlSm\">\u512a\u5316\u67e5\u8a62\u6027\u80fd\u7684\u5efa\u8b70<\/h2>\n<p>\u6839\u64da EXPLAIN \u7684\u8f38\u51fa\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u63a1\u53d6\u4ee5\u4e0b\u5e7e\u500b\u6b65\u9a5f\u4f86\u512a\u5316\u67e5\u8a62\u6027\u80fd\uff1a<\/p>\n<ul>\n<li><strong>\u4f7f\u7528\u7d22\u5f15\uff1a<\/strong>\u78ba\u4fdd\u67e5\u8a62\u4e2d\u4f7f\u7528\u4e86\u5408\u9069\u7684\u7d22\u5f15\uff0c\u4ee5\u6e1b\u5c11\u6383\u63cf\u7684\u884c\u6578\u3002<\/li>\n<li><strong>\u907f\u514d\u5168\u8868\u6383\u63cf\uff1a<\/strong>\u5982\u679c\u67e5\u8a62\u7684 <code>type<\/code> \u986f\u793a\u70ba <code>ALL<\/code>\uff0c\u5247\u8868\u793a\u9032\u884c\u4e86\u5168\u8868\u6383\u63cf\uff0c\u9019\u901a\u5e38\u662f\u6027\u80fd\u74f6\u9838\u3002<\/li>\n<li><strong>\u7c21\u5316\u67e5\u8a62\uff1a<\/strong>\u5c07\u8907\u96dc\u7684\u67e5\u8a62\u62c6\u5206\u70ba\u591a\u500b\u7c21\u55ae\u67e5\u8a62\uff0c\u53ef\u80fd\u6703\u63d0\u9ad8\u6027\u80fd\u3002<\/li>\n<li><strong>\u5b9a\u671f\u5206\u6790\u8868\uff1a<\/strong>\u4f7f\u7528 <code>ANALYZE TABLE<\/code> \u547d\u4ee4\u4f86\u66f4\u65b0\u8868\u7684\u7d71\u8a08\u4fe1\u606f\uff0c\u5e6b\u52a9\u512a\u5316\u5668\u505a\u51fa\u66f4\u597d\u7684\u6c7a\u7b56\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-hLDeLGqlSm\">\u7e3d\u7d50<\/h2>\n<p>OceanBase \u7684 EXPLAIN \u8a9e\u53e5\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u6df1\u5165\u4e86\u89e3\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u901a\u904e\u5206\u6790 EXPLAIN \u7684\u8f38\u51fa\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8b58\u5225\u6027\u80fd\u74f6\u9838\u4e26\u9032\u884c\u76f8\u61c9\u7684\u512a\u5316\u3002\u7121\u8ad6\u662f\u5927\u578b\u4f01\u696d\u9084\u662f\u4e2d\u5c0f\u578b\u4f01\u696d\uff0c\u5408\u7406\u5229\u7528 OceanBase \u7684\u529f\u80fd\u90fd\u80fd\u986f\u8457\u63d0\u5347\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u6548\u7387\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\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f\u5176\u4ed6\u96f2\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Learn how to use OceanBase EXPLAIN for efficient query analysis and optimization in this comprehensive tutorial. Enhance your database performance today!<\/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-160129","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160129","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=160129"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160129\/revisions"}],"predecessor-version":[{"id":160130,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160129\/revisions\/160130"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160129"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160129"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160129"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}