{"id":185970,"date":"2024-11-11T02:01:18","date_gmt":"2024-11-10T18:01:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/185970\/"},"modified":"2024-11-11T02:01:19","modified_gmt":"2024-11-10T18:01:19","slug":"%e6%95%b8%e6%93%9a%e5%ba%abindex%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7%e5%8f%8a%e4%bd%9c%e7%94%a8%ef%bc%88%e6%95%b8%e6%93%9a%e5%ba%abindex%e4%bd%9c%e7%94%a8%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/185970\/","title":{"rendered":"\u6578\u64da\u5eabindex\u7684\u91cd\u8981\u6027\u53ca\u4f5c\u7528\uff08\u6578\u64da\u5eabindex\u4f5c\u7528\uff09"},"content":{"rendered":"<h1 id=\"%e6%95%b8%e6%93%9a%e5%ba%abindex%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7%e5%8f%8a%e4%bd%9c%e7%94%a8-ZHxGtiDAQB\">\u6578\u64da\u5eabIndex\u7684\u91cd\u8981\u6027\u53ca\u4f5c\u7528<\/h1>\n<p>\u5728\u73fe\u4ee3\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u6578\u64da\u5eabIndex\uff08\u7d22\u5f15\uff09\u662f\u4e00\u500b\u4e0d\u53ef\u6216\u7f3a\u7684\u7d44\u4ef6\u3002\u5b83\u7684\u4e3b\u8981\u4f5c\u7528\u662f\u63d0\u9ad8\u6578\u64da\u6aa2\u7d22\u7684\u6548\u7387\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eabIndex\u7684\u91cd\u8981\u6027\u53ca\u5176\u5177\u9ad4\u4f5c\u7528\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e6%95%b8%e6%93%9a%e5%ba%abindex%ef%bc%9f-ZHxGtiDAQB\">\u4ec0\u9ebc\u662f\u6578\u64da\u5eabIndex\uff1f<\/h2>\n<p>\u6578\u64da\u5eabIndex\u662f\u4e00\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u65e8\u5728\u52a0\u901f\u67e5\u8a62\u64cd\u4f5c\u3002\u5b83\u985e\u4f3c\u65bc\u66f8\u7c4d\u7684\u76ee\u9304\uff0c\u5e6b\u52a9\u7528\u6236\u5feb\u901f\u627e\u5230\u6240\u9700\u7684\u4fe1\u606f\u3002\u7576\u6578\u64da\u5eab\u8868\u4e2d\u7684\u6578\u64da\u91cf\u589e\u5927\u6642\uff0c\u6c92\u6709Index\u7684\u67e5\u8a62\u53ef\u80fd\u9700\u8981\u6383\u63cf\u6574\u500b\u8868\uff0c\u9019\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e5%ba%abindex%e7%9a%84%e9%a1%9e%e5%9e%8b-ZHxGtiDAQB\">\u6578\u64da\u5eabIndex\u7684\u985e\u578b<\/h2>\n<ul>\n<li><strong>B-Tree Index\uff1a<\/strong>\u6700\u5e38\u898b\u7684\u7d22\u5f15\u985e\u578b\uff0c\u9069\u7528\u65bc\u7bc4\u570d\u67e5\u8a62\u548c\u6392\u5e8f\u64cd\u4f5c\u3002<\/li>\n<li><strong>Hash Index\uff1a<\/strong>\u9069\u5408\u7cbe\u78ba\u67e5\u8a62\uff0c\u4f46\u4e0d\u652f\u6301\u7bc4\u570d\u67e5\u8a62\u3002<\/li>\n<li><strong>Full-Text Index\uff1a<\/strong>\u7528\u65bc\u6587\u672c\u641c\u7d22\uff0c\u80fd\u5920\u5feb\u901f\u67e5\u627e\u5305\u542b\u7279\u5b9a\u55ae\u8a5e\u7684\u8a18\u9304\u3002<\/li>\n<li><strong>Composite Index\uff1a<\/strong>\u7531\u591a\u500b\u5217\u7d44\u6210\u7684\u7d22\u5f15\uff0c\u9069\u5408\u8907\u96dc\u67e5\u8a62\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%95%b8%e6%93%9a%e5%ba%abindex%e7%9a%84%e4%bd%9c%e7%94%a8-ZHxGtiDAQB\">\u6578\u64da\u5eabIndex\u7684\u4f5c\u7528<\/h2>\n<h3 id=\"1-%e6%8f%90%e9%ab%98%e6%9f%a5%e8%a9%a2%e6%80%a7%e8%83%bd-ZHxGtiDAQB\">1. \u63d0\u9ad8\u67e5\u8a62\u6027\u80fd<\/h3>\n<p>\u6578\u64da\u5eabIndex\u7684\u4e3b\u8981\u4f5c\u7528\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u7576\u57f7\u884c\u67e5\u8a62\u6642\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u5229\u7528Index\u5feb\u901f\u5b9a\u4f4d\u5230\u6240\u9700\u7684\u6578\u64da\uff0c\u800c\u4e0d\u5fc5\u9010\u884c\u6383\u63cf\u6574\u500b\u8868\u3002\u4f8b\u5982\uff0c\u8003\u616e\u4ee5\u4e0bSQL\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT * FROM users WHERE username = 'john_doe';<\/code><\/pre>\n<p>\u5982\u679c\u5728username\u5217\u4e0a\u5275\u5efa\u4e86Index\uff0c\u6578\u64da\u5eab\u5c07\u80fd\u5920\u8fc5\u901f\u627e\u5230\u5339\u914d\u7684\u8a18\u9304\uff0c\u5f9e\u800c\u986f\u8457\u6e1b\u5c11\u67e5\u8a62\u6642\u9593\u3002<\/p>\n<h3 id=\"2-%e9%99%8d%e4%bd%8ei-o%e6%93%8d%e4%bd%9c-ZHxGtiDAQB\">2. \u964d\u4f4eI\/O\u64cd\u4f5c<\/h3>\n<p>\u4f7f\u7528Index\u53ef\u4ee5\u6e1b\u5c11\u78c1\u789fI\/O\u64cd\u4f5c\u7684\u6b21\u6578\u3002\u7576\u6578\u64da\u5eab\u9700\u8981\u8b80\u53d6\u6578\u64da\u6642\uff0c\u4f7f\u7528Index\u53ef\u4ee5\u76f4\u63a5\u5b9a\u4f4d\u5230\u6578\u64da\u6240\u5728\u7684\u9801\u9762\uff0c\u800c\u4e0d\u5fc5\u8b80\u53d6\u6574\u500b\u8868\u3002\u9019\u5c0d\u65bc\u5927\u578b\u6578\u64da\u96c6\u5c24\u70ba\u91cd\u8981\uff0c\u56e0\u70baI\/O\u64cd\u4f5c\u901a\u5e38\u662f\u6027\u80fd\u74f6\u9838\u3002<\/p>\n<h3 id=\"3-%e6%94%af%e6%8c%81%e6%8e%92%e5%ba%8f%e5%92%8c%e5%88%86%e7%b5%84-ZHxGtiDAQB\">3. \u652f\u6301\u6392\u5e8f\u548c\u5206\u7d44<\/h3>\n<p>Index\u9084\u53ef\u4ee5\u52a0\u901fORDER BY\u548cGROUP BY\u64cd\u4f5c\u3002\u7576\u67e5\u8a62\u9700\u8981\u5c0d\u7d50\u679c\u9032\u884c\u6392\u5e8f\u6216\u5206\u7d44\u6642\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u5229\u7528Index\u4f86\u5feb\u901f\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT * FROM orders ORDER BY order_date DESC;<\/code><\/pre>\n<p>\u5982\u679c\u5728order_date\u5217\u4e0a\u6709Index\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u8a72Index\u4f86\u8fd4\u56de\u6392\u5e8f\u7d50\u679c\uff0c\u800c\u7121\u9700\u984d\u5916\u7684\u6392\u5e8f\u64cd\u4f5c\u3002<\/p>\n<h3 id=\"4-%e6%8f%90%e9%ab%98%e5%94%af%e4%b8%80%e6%80%a7%e7%b4%84%e6%9d%9f-ZHxGtiDAQB\">4. \u63d0\u9ad8\u552f\u4e00\u6027\u7d04\u675f<\/h3>\n<p>Index\u9084\u53ef\u4ee5\u7528\u65bc\u5f37\u5236\u552f\u4e00\u6027\u7d04\u675f\u3002\u4f8b\u5982\uff0c\u5728\u5275\u5efa\u4e00\u500b\u7528\u6236\u8868\u6642\uff0c\u53ef\u4ee5\u5728email\u5217\u4e0a\u5275\u5efa\u552f\u4e00\u7d22\u5f15\uff0c\u4ee5\u78ba\u4fdd\u6bcf\u500b\u7528\u6236\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u90fd\u662f\u552f\u4e00\u7684\uff1a<\/p>\n<pre><code>CREATE UNIQUE INDEX idx_email ON users(email);<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u9632\u6b62\u91cd\u8907\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u63d2\u5165\u5230\u8868\u4e2d\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-ZHxGtiDAQB\">\u7d50\u8ad6<\/h2>\n<p>\u6578\u64da\u5eabIndex\u5728\u6578\u64da\u6aa2\u7d22\u4e2d\u626e\u6f14\u8457\u81f3\u95dc\u91cd\u8981\u7684\u89d2\u8272\u3002\u5b83\u4e0d\u50c5\u63d0\u9ad8\u4e86\u67e5\u8a62\u6027\u80fd\uff0c\u9084\u964d\u4f4e\u4e86I\/O\u64cd\u4f5c\u7684\u6b21\u6578\uff0c\u652f\u6301\u6392\u5e8f\u548c\u5206\u7d44\uff0c\u4e26\u5f37\u5316\u4e86\u6578\u64da\u7684\u552f\u4e00\u6027\u7d04\u675f\u3002\u5c0d\u65bc\u4efb\u4f55\u5e0c\u671b\u512a\u5316\u6578\u64da\u5eab\u6027\u80fd\u7684\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u4f86\u8aaa\uff0c\u7406\u89e3\u548c\u6b63\u78ba\u4f7f\u7528Index\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u548c\u512a\u5316\u7684\u8cc7\u8a0a\uff0c\u60a8\u53ef\u4ee5\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9 <a href=\"https:\/\/server.hk\">Server.HK<\/a>\uff0c\u63a2\u7d22\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u53ca\u5176\u4ed6\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u6578\u64da\u5eab\u7d22\u5f15\u7684\u91cd\u8981\u6027\u53ca\u4f5c\u7528\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff0c\u512a\u5316\u6578\u64da\u5b58\u53d6\uff0c\u78ba\u4fdd\u7cfb\u7d71\u6027\u80fd\u8207\u97ff\u61c9\u901f\u5ea6\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-185970","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185970","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=185970"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185970\/revisions"}],"predecessor-version":[{"id":185971,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185970\/revisions\/185971"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=185970"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=185970"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=185970"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}