{"id":172589,"date":"2024-11-07T14:23:22","date_gmt":"2024-11-07T06:23:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/172589\/"},"modified":"2024-11-07T14:23:23","modified_gmt":"2024-11-07T06:23:23","slug":"%e5%a6%82%e4%bd%95%e6%9f%a5%e7%9c%8bmysql%e7%b4%a2%e5%bc%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/172589\/","title":{"rendered":"\u5982\u4f55\u67e5\u770bMySQL\u7d22\u5f15"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e6%9f%a5%e7%9c%8bmysql%e7%b4%a2%e5%bc%95-nRBKgQIAMt\">\u5982\u4f55\u67e5\u770bMySQL\u7d22\u5f15<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u7d22\u5f15\u662f\u4e00\u500b\u81f3\u95dc\u91cd\u8981\u7684\u6982\u5ff5\u3002\u5b83\u80fd\u5920\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u7684\u6548\u7387\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002MySQL\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u958b\u6e90\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u67e5\u770b\u548c\u7ba1\u7406\u7d22\u5f15\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u5982\u4f55\u5728MySQL\u4e2d\u67e5\u770b\u7d22\u5f15\u7684\u8a73\u7d30\u6b65\u9a5f\u548c\u76f8\u95dc\u547d\u4ee4\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afmysql%e7%b4%a2%e5%bc%95%ef%bc%9f-nRBKgQIAMt\">\u4ec0\u9ebc\u662fMySQL\u7d22\u5f15\uff1f<\/h2>\n<p>\u7d22\u5f15\u662f\u4e00\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u65e8\u5728\u63d0\u9ad8\u6578\u64da\u6aa2\u7d22\u7684\u901f\u5ea6\u3002\u5b83\u985e\u4f3c\u65bc\u66f8\u7c4d\u7684\u76ee\u9304\uff0c\u80fd\u5920\u5e6b\u52a9\u6578\u64da\u5eab\u5feb\u901f\u5b9a\u4f4d\u5230\u6240\u9700\u7684\u6578\u64da\u3002MySQL\u652f\u6301\u591a\u7a2e\u7d22\u5f15\u985e\u578b\uff0c\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong>B-Tree\u7d22\u5f15\uff1a<\/strong>\u6700\u5e38\u7528\u7684\u7d22\u5f15\u985e\u578b\uff0c\u9069\u7528\u65bc\u7bc4\u570d\u67e5\u8a62\u3002<\/li>\n<li><strong>\u54c8\u5e0c\u7d22\u5f15\uff1a<\/strong>\u4e3b\u8981\u7528\u65bc\u7b49\u503c\u67e5\u8a62\uff0c\u901f\u5ea6\u5feb\u4f46\u4e0d\u652f\u6301\u7bc4\u570d\u67e5\u8a62\u3002<\/li>\n<li><strong>\u5168\u6587\u7d22\u5f15\uff1a<\/strong>\u5c08\u9580\u7528\u65bc\u6587\u672c\u641c\u7d22\uff0c\u9069\u5408\u67e5\u8a62\u5927\u91cf\u6587\u672c\u6578\u64da\u3002<\/li>\n<li><strong>\u7a7a\u9593\u7d22\u5f15\uff1a<\/strong>\u7528\u65bc\u5730\u7406\u6578\u64da\u7684\u67e5\u8a62\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%9f%a5%e7%9c%8bmysql%e7%b4%a2%e5%bc%95%e7%9a%84%e6%96%b9%e6%b3%95-nRBKgQIAMt\">\u67e5\u770bMySQL\u7d22\u5f15\u7684\u65b9\u6cd5<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u6709\u5e7e\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u67e5\u770b\u8868\u7684\u7d22\u5f15\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8show-index%e5%91%bd%e4%bb%a4-nRBKgQIAMt\">1. \u4f7f\u7528SHOW INDEX\u547d\u4ee4<\/h3>\n<p>\u6700\u76f4\u63a5\u7684\u65b9\u6cd5\u662f\u4f7f\u7528<code>SHOW INDEX<\/code>\u547d\u4ee4\u3002\u9019\u500b\u547d\u4ee4\u53ef\u4ee5\u986f\u793a\u6307\u5b9a\u8868\u7684\u6240\u6709\u7d22\u5f15\u4fe1\u606f\u3002\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SHOW INDEX FROM \u8868\u540d;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba<code>users<\/code>\u7684\u8868\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\u67e5\u770b\u7d22\u5f15\uff1a<\/p>\n<pre><code>SHOW INDEX FROM users;<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de\u4e00\u500b\u7d50\u679c\u96c6\uff0c\u5176\u4e2d\u5305\u542b\u7d22\u5f15\u7684\u540d\u7a31\u3001\u985e\u578b\u3001\u552f\u4e00\u6027\u3001\u5217\u540d\u7b49\u4fe1\u606f\u3002<\/p>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8information_schema-nRBKgQIAMt\">2. \u4f7f\u7528INFORMATION_SCHEMA<\/h3>\n<p>\u53e6\u4e00\u7a2e\u67e5\u770b\u7d22\u5f15\u7684\u65b9\u6cd5\u662f\u67e5\u8a62<code>INFORMATION_SCHEMA<\/code>\u6578\u64da\u5eab\u3002\u9019\u662f\u4e00\u500b\u865b\u64ec\u6578\u64da\u5eab\uff0c\u5305\u542b\u4e86\u6240\u6709\u6578\u64da\u5eab\u7684\u5143\u6578\u64da\u3002\u8981\u67e5\u770b\u7279\u5b9a\u8868\u7684\u7d22\u5f15\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT * FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_NAME = '\u8868\u540d';<\/code><\/pre>\n<p>\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT * FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_NAME = 'users';<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de\u8207<code>SHOW INDEX<\/code>\u547d\u4ee4\u76f8\u4f3c\u7684\u4fe1\u606f\uff0c\u4f46\u53ef\u4ee5\u9032\u884c\u66f4\u9748\u6d3b\u7684\u67e5\u8a62\u548c\u904e\u6ffe\u3002<\/p>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8explain%e5%91%bd%e4%bb%a4-nRBKgQIAMt\">3. \u4f7f\u7528EXPLAIN\u547d\u4ee4<\/h3>\n<p>\u5982\u679c\u60f3\u8981\u4e86\u89e3\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u53ca\u5176\u4f7f\u7528\u7684\u7d22\u5f15\uff0c\u53ef\u4ee5\u4f7f\u7528<code>EXPLAIN<\/code>\u547d\u4ee4\u3002\u9019\u500b\u547d\u4ee4\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u512a\u5316\u67e5\u8a62\u6027\u80fd\u3002\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>EXPLAIN SELECT * FROM \u8868\u540d WHERE \u689d\u4ef6;<\/code><\/pre>\n<p>\u4f8b\u5982\uff1a<\/p>\n<pre><code>EXPLAIN SELECT * FROM users WHERE age &gt; 30;<\/code><\/pre>\n<p>\u57f7\u884c\u9019\u500b\u547d\u4ee4\u5f8c\uff0cMySQL\u6703\u8fd4\u56de\u4e00\u500b\u7d50\u679c\u96c6\uff0c\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5305\u62ec\u4f7f\u7528\u7684\u7d22\u5f15\u3002<\/p>\n<h2 id=\"%e7%b4%a2%e5%bc%95%e7%9a%84%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-nRBKgQIAMt\">\u7d22\u5f15\u7684\u6700\u4f73\u5be6\u8e10<\/h2>\n<p>\u5728\u4f7f\u7528\u7d22\u5f15\u6642\uff0c\u61c9\u9075\u5faa\u4e00\u4e9b\u6700\u4f73\u5be6\u8e10\uff0c\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u6027\u80fd\u7684\u6700\u4f73\u5316\uff1a<\/p>\n<ul>\n<li>\u907f\u514d\u5728\u983b\u7e41\u66f4\u65b0\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u56e0\u70ba\u9019\u6703\u5f71\u97ff\u5beb\u5165\u6027\u80fd\u3002<\/li>\n<li>\u5c0d\u65bc\u67e5\u8a62\u983b\u7e41\u7684\u5217\uff0c\u8003\u616e\u5275\u5efa\u7d22\u5f15\u4ee5\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\u3002<\/li>\n<li>\u5b9a\u671f\u6aa2\u67e5\u548c\u512a\u5316\u7d22\u5f15\uff0c\u522a\u9664\u4e0d\u518d\u4f7f\u7528\u7684\u7d22\u5f15\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-nRBKgQIAMt\">\u7e3d\u7d50<\/h2>\n<p>\u4e86\u89e3\u5982\u4f55\u67e5\u770b\u548c\u7ba1\u7406MySQL\u7d22\u5f15\u5c0d\u65bc\u6578\u64da\u5eab\u6027\u80fd\u7684\u512a\u5316\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u4f7f\u7528<code>SHOW INDEX<\/code>\u3001<code>INFORMATION_SCHEMA<\/code>\u548c<code>EXPLAIN<\/code>\u7b49\u547d\u4ee4\uff0c\u60a8\u53ef\u4ee5\u8f15\u9b06\u7372\u53d6\u7d22\u5f15\u4fe1\u606f\u4e26\u9032\u884c\u76f8\u61c9\u7684\u8abf\u6574\u3002\u82e5\u60a8\u9700\u8981\u66f4\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u4f86\u63d0\u5347\u60a8\u7684\u61c9\u7528\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u67e5\u770bMySQL\u7d22\u5f15\uff0c\u638c\u63e1\u4f7f\u7528SHOW INDEX\u547d\u4ee4\u548cINFORMATION_SCHEMA\u83b7\u53d6\u7d22\u5f15\u4fe1\u606f\u7684\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-172589","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172589","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=172589"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172589\/revisions"}],"predecessor-version":[{"id":172590,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172589\/revisions\/172590"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=172589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=172589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=172589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}