{"id":77216,"date":"2024-10-16T10:33:17","date_gmt":"2024-10-16T02:33:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/77216\/"},"modified":"2024-10-16T10:33:17","modified_gmt":"2024-10-16T02:33:17","slug":"mysql%e4%bf%ae%e6%94%b9%e8%a1%a8%e7%b5%90%e6%a7%8b%e4%b8%ad%e5%b0%8d%e7%b4%a2%e5%bc%95%e7%9a%84%e6%93%8d%e4%bd%9c","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/77216\/","title":{"rendered":"MySQL\u4fee\u6539\u8868\u7d50\u69cb\u4e2d\u5c0d\u7d22\u5f15\u7684\u64cd\u4f5c"},"content":{"rendered":"<h1 id=\"mysql%e4%bf%ae%e6%94%b9%e8%a1%a8%e7%b5%90%e6%a7%8b%e4%b8%ad%e5%b0%8d%e7%b4%a2%e5%bc%95%e7%9a%84%e6%93%8d%e4%bd%9c-JtlJkKpzuJ\">MySQL\u4fee\u6539\u8868\u7d50\u69cb\u4e2d\u5c0d\u7d22\u5f15\u7684\u64cd\u4f5c<\/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\u4fee\u6539\u8868\u7d50\u69cb\u4e2d\u7684\u7d22\u5f15\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u5982\u4f55\u5728MySQL\u4e2d\u9032\u884c\u7d22\u5f15\u7684\u64cd\u4f5c\uff0c\u5305\u62ec\u6dfb\u52a0\u3001\u522a\u9664\u548c\u4fee\u6539\u7d22\u5f15\u3002<\/p>\n<h2 id=\"%e7%b4%a2%e5%bc%95%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-JtlJkKpzuJ\">\u7d22\u5f15\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u7d22\u5f15\u662f\u4e00\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u80fd\u5920\u52a0\u901f\u6578\u64da\u6aa2\u7d22\u7684\u901f\u5ea6\u3002\u5b83\u985e\u4f3c\u65bc\u66f8\u7c4d\u7684\u76ee\u9304\uff0c\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<\/strong>\uff1a\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<\/strong>\uff1a\u9069\u5408\u7cbe\u78ba\u67e5\u8a62\uff0c\u4f46\u4e0d\u652f\u6301\u7bc4\u570d\u67e5\u8a62\u3002<\/li>\n<li><strong>\u5168\u6587\u7d22\u5f15<\/strong>\uff1a\u5c08\u9580\u7528\u65bc\u6587\u672c\u641c\u7d22\u3002<\/li>\n<li><strong>\u7a7a\u9593\u7d22\u5f15<\/strong>\uff1a\u7528\u65bc\u5730\u7406\u6578\u64da\u7684\u67e5\u8a62\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%b7%bb%e5%8a%a0%e7%b4%a2%e5%bc%95-JtlJkKpzuJ\">\u6dfb\u52a0\u7d22\u5f15<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u4f86\u6dfb\u52a0\u7d22\u5f15\u3002\u4ee5\u4e0b\u662f\u6dfb\u52a0\u7d22\u5f15\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d ADD INDEX \u7d22\u5f15\u540d (\u5217\u540d);<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba\u201cusers\u201d\u7684\u8868\uff0c\u4e26\u5e0c\u671b\u5728\u201cemail\u201d\u5217\u4e0a\u6dfb\u52a0\u7d22\u5f15\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\uff1a<\/p>\n<pre><code>ALTER TABLE users ADD INDEX idx_email (email);<\/code><\/pre>\n<h2 id=\"%e5%88%aa%e9%99%a4%e7%b4%a2%e5%bc%95-JtlJkKpzuJ\">\u522a\u9664\u7d22\u5f15<\/h2>\n<p>\u5982\u679c\u4e0d\u518d\u9700\u8981\u67d0\u500b\u7d22\u5f15\uff0c\u53ef\u4ee5\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u522a\u9664\u5b83\u3002\u522a\u9664\u7d22\u5f15\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d DROP INDEX \u7d22\u5f15\u540d;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u522a\u9664\u525b\u624d\u5275\u5efa\u7684\u201cidx_email\u201d\u7d22\u5f15\uff0c\u53ef\u4ee5\u57f7\u884c\u4ee5\u4e0b\u547d\u4ee4\uff1a<\/p>\n<pre><code>ALTER TABLE users DROP INDEX idx_email;<\/code><\/pre>\n<h2 id=\"%e4%bf%ae%e6%94%b9%e7%b4%a2%e5%bc%95-JtlJkKpzuJ\">\u4fee\u6539\u7d22\u5f15<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u76f4\u63a5\u4fee\u6539\u7d22\u5f15\u4e26\u4e0d\u652f\u6301\u3002\u82e5\u9700\u8981\u66f4\u6539\u7d22\u5f15\u7684\u7d50\u69cb\uff0c\u901a\u5e38\u9700\u8981\u5148\u522a\u9664\u820a\u7684\u7d22\u5f15\uff0c\u7136\u5f8c\u518d\u6dfb\u52a0\u65b0\u7684\u7d22\u5f15\u3002\u4f8b\u5982\uff0c\u82e5\u8981\u5c07\u201cemail\u201d\u5217\u7684\u7d22\u5f15\u6539\u70ba\u552f\u4e00\u7d22\u5f15\uff0c\u53ef\u4ee5\u9019\u6a23\u64cd\u4f5c\uff1a<\/p>\n<pre><code>ALTER TABLE users DROP INDEX idx_email;\nALTER TABLE users ADD UNIQUE INDEX idx_email (email);<\/code><\/pre>\n<h2 id=\"%e7%b4%a2%e5%bc%95%e7%9a%84%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-JtlJkKpzuJ\">\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>\u50c5\u5728\u5fc5\u8981\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u904e\u591a\u7684\u7d22\u5f15\u6703\u5f71\u97ff\u5beb\u5165\u6027\u80fd\u3002<\/li>\n<li>\u5b9a\u671f\u6aa2\u67e5\u548c\u91cd\u5efa\u7d22\u5f15\uff0c\u4ee5\u4fdd\u6301\u5176\u6548\u7387\u3002<\/li>\n<li>\u4f7f\u7528EXPLAIN\u8a9e\u53e5\u4f86\u5206\u6790\u67e5\u8a62\u6027\u80fd\uff0c\u78ba\u4fdd\u7d22\u5f15\u7684\u6709\u6548\u6027\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-JtlJkKpzuJ\">\u7e3d\u7d50<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u5c0d\u7d22\u5f15\u7684\u64cd\u4f5c\u662f\u6578\u64da\u5eab\u7ba1\u7406\u7684\u91cd\u8981\u7d44\u6210\u90e8\u5206\u3002\u901a\u904e\u6b63\u78ba\u5730\u6dfb\u52a0\u3001\u522a\u9664\u548c\u4fee\u6539\u7d22\u5f15\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u4e86\u89e3\u7d22\u5f15\u7684\u57fa\u672c\u6982\u5ff5\u53ca\u5176\u64cd\u4f5c\u65b9\u6cd5\uff0c\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u4f86\u8aaa\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684\u6280\u80fd\u3002\u82e5\u60a8\u9700\u8981\u9032\u4e00\u6b65\u4e86\u89e3\u5982\u4f55\u512a\u5316\u60a8\u7684\u6578\u64da\u5eab\u6027\u80fd\uff0c\u6216\u5c0b\u627e\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u4fe1\u606f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u4e2d\u4fee\u6539\u8868\u7d50\u69cb\u6642\u5c0d\u7d22\u5f15\u7684\u64cd\u4f5c\uff0c\u5305\u62ec\u6dfb\u52a0\u3001\u522a\u9664\u548c\u4fee\u6539\u7d22\u5f15\u7684\u6b65\u9a5f\u8207\u6ce8\u610f\u4e8b\u9805\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-77216","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77216","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=77216"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77216\/revisions"}],"predecessor-version":[{"id":77217,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77216\/revisions\/77217"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=77216"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=77216"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=77216"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}