{"id":186258,"date":"2024-11-11T04:25:23","date_gmt":"2024-11-10T20:25:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/186258\/"},"modified":"2024-11-11T04:25:24","modified_gmt":"2024-11-10T20:25:24","slug":"%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%ae%97%e6%b3%95-%e5%84%aa%e5%8c%96%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a7%a3%e6%b1%ba%e6%96%b9%e6%a1%88-%e6%95%b8%e6%93%9a%e5%ba%ab-%e6%9f%a5%e8%a9%a2","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/186258\/","title":{"rendered":"\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5 \u512a\u5316\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848 (\u6578\u64da\u5eab \u67e5\u8a62\u7b97\u6cd5)"},"content":{"rendered":"<h1 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%ae%97%e6%b3%95-%e5%84%aa%e5%8c%96%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a7%a3%e6%b1%ba%e6%96%b9%e6%a1%88-fsWvaVoGCV\">\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5 \u512a\u5316\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u6027\u80fd\u5c0d\u65bc\u61c9\u7528\u7a0b\u5e8f\u7684\u6574\u9ad4\u6548\u7387\u81f3\u95dc\u91cd\u8981\u3002\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5\u7684\u512a\u5316\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\uff0c\u9084\u80fd\u6e1b\u5c11\u8cc7\u6e90\u6d88\u8017\uff0c\u5f9e\u800c\u63d0\u5347\u7528\u6236\u9ad4\u9a57\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5\u7684\u57fa\u672c\u6982\u5ff5\u3001\u5e38\u898b\u7684\u512a\u5316\u6280\u8853\u4ee5\u53ca\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u793a\u4f8b\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%ae%97%e6%b3%95%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-fsWvaVoGCV\">\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5\u662f\u6307\u7528\u65bc\u6aa2\u7d22\u6578\u64da\u7684\u8a08\u7b97\u65b9\u6cd5\u3002\u9019\u4e9b\u7b97\u6cd5\u7684\u6548\u7387\u76f4\u63a5\u5f71\u97ff\u5230\u6578\u64da\u5eab\u7684\u6027\u80fd\u3002\u5e38\u898b\u7684\u67e5\u8a62\u7b97\u6cd5\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong>\u5168\u8868\u6383\u63cf\uff08Full Table Scan\uff09<\/strong>\uff1a\u9019\u662f\u4e00\u7a2e\u6700\u57fa\u672c\u7684\u67e5\u8a62\u65b9\u5f0f\uff0c\u6578\u64da\u5eab\u6703\u6aa2\u67e5\u6bcf\u4e00\u884c\u4ee5\u627e\u5230\u7b26\u5408\u689d\u4ef6\u7684\u6578\u64da\u3002\u96d6\u7136\u7c21\u55ae\uff0c\u4f46\u5728\u6578\u64da\u91cf\u9f90\u5927\u7684\u60c5\u6cc1\u4e0b\u6548\u7387\u6975\u4f4e\u3002<\/li>\n<li><strong>\u7d22\u5f15\u67e5\u8a62\uff08Index Scan\uff09<\/strong>\uff1a\u901a\u904e\u4f7f\u7528\u7d22\u5f15\u4f86\u52a0\u901f\u67e5\u8a62\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u5feb\u901f\u5b9a\u4f4d\u5230\u7b26\u5408\u689d\u4ef6\u7684\u6578\u64da\u884c\uff0c\u5f9e\u800c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/li>\n<li><strong>\u806f\u63a5\u67e5\u8a62\uff08Join Query\uff09<\/strong>\uff1a\u7576\u9700\u8981\u5f9e\u591a\u500b\u8868\u4e2d\u6aa2\u7d22\u6578\u64da\u6642\uff0c\u806f\u63a5\u67e5\u8a62\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684\u3002\u6839\u64da\u806f\u63a5\u7684\u985e\u578b\uff08\u5982\u5167\u806f\u63a5\u3001\u5916\u806f\u63a5\u7b49\uff09\uff0c\u6027\u80fd\u6703\u6709\u6240\u4e0d\u540c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%84%aa%e5%8c%96%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%9a%84%e6%8a%80%e8%a1%93-fsWvaVoGCV\">\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u7684\u6280\u8853<\/h2>\n<p>\u70ba\u4e86\u63d0\u9ad8\u6578\u64da\u5eab\u67e5\u8a62\u7684\u6027\u80fd\uff0c\u53ef\u4ee5\u63a1\u53d6\u4ee5\u4e0b\u5e7e\u7a2e\u512a\u5316\u6280\u8853\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95-fsWvaVoGCV\">1. \u4f7f\u7528\u7d22\u5f15<\/h3>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u95dc\u9375\u3002\u901a\u904e\u5728\u8868\u7684\u67d0\u4e9b\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u53ef\u4ee5\u986f\u8457\u6e1b\u5c11\u67e5\u8a62\u6240\u9700\u7684\u6642\u9593\u3002\u4ee5\u4e0b\u662f\u5275\u5efa\u7d22\u5f15\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>CREATE INDEX idx_column_name ON table_name (column_name);<\/code><\/pre>\n<p>\u7136\u800c\uff0c\u904e\u591a\u7684\u7d22\u5f15\u6703\u5f71\u97ff\u6578\u64da\u7684\u5beb\u5165\u6027\u80fd\uff0c\u56e0\u6b64\u9700\u8981\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u9032\u884c\u5e73\u8861\u3002<\/p>\n<h3 id=\"2-%e6%9f%a5%e8%a9%a2%e9%87%8d%e5%af%ab-fsWvaVoGCV\">2. \u67e5\u8a62\u91cd\u5beb<\/h3>\n<p>\u6709\u6642\u5019\uff0c\u901a\u904e\u91cd\u5beb\u67e5\u8a62\u8a9e\u53e5\u53ef\u4ee5\u63d0\u9ad8\u6027\u80fd\u3002\u4f8b\u5982\uff0c\u5c07\u591a\u500b\u67e5\u8a62\u5408\u4f75\u70ba\u4e00\u500b\u67e5\u8a62\uff0c\u6216\u4f7f\u7528\u5b50\u67e5\u8a62\u4f86\u6e1b\u5c11\u6578\u64da\u7684\u8655\u7406\u91cf\u3002<\/p>\n<pre><code>SELECT * FROM table1 WHERE id IN (SELECT id FROM table2 WHERE condition);<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8%e7%b7%a9%e5%ad%98-fsWvaVoGCV\">3. \u4f7f\u7528\u7de9\u5b58<\/h3>\n<p>\u7de9\u5b58\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u7279\u5225\u662f\u5c0d\u65bc\u91cd\u8907\u67e5\u8a62\u7684\u60c5\u6cc1\u3002\u901a\u904e\u5c07\u67e5\u8a62\u7d50\u679c\u5b58\u5132\u5728\u5167\u5b58\u4e2d\uff0c\u53ef\u4ee5\u907f\u514d\u91cd\u8907\u7684\u8a08\u7b97\u548c\u6578\u64da\u6aa2\u7d22\u3002<\/p>\n<h3 id=\"4-%e5%88%86%e5%8d%80%e8%a1%a8-fsWvaVoGCV\">4. \u5206\u5340\u8868<\/h3>\n<p>\u5c0d\u65bc\u5927\u578b\u6578\u64da\u96c6\uff0c\u4f7f\u7528\u5206\u5340\u8868\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u901a\u904e\u5c07\u6578\u64da\u5206\u6563\u5230\u4e0d\u540c\u7684\u7269\u7406\u5340\u57df\uff0c\u53ef\u4ee5\u6e1b\u5c11\u6bcf\u6b21\u67e5\u8a62\u6240\u9700\u6383\u63cf\u7684\u6578\u64da\u91cf\u3002<\/p>\n<h2 id=\"%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8%e4%b8%ad%e7%9a%84%e7%a4%ba%e4%be%8b-fsWvaVoGCV\">\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u793a\u4f8b<\/h2>\n<p>\u5047\u8a2d\u6709\u4e00\u500b\u96fb\u5b50\u5546\u52d9\u7db2\u7ad9\uff0c\u6578\u64da\u5eab\u4e2d\u5b58\u5132\u4e86\u5927\u91cf\u7684\u7522\u54c1\u4fe1\u606f\u548c\u7528\u6236\u8a02\u55ae\u3002\u7576\u7528\u6236\u67e5\u8a62\u67d0\u500b\u7522\u54c1\u7684\u8a02\u55ae\u6642\uff0c\u5982\u679c\u6c92\u6709\u9069\u7576\u7684\u7d22\u5f15\uff0c\u67e5\u8a62\u53ef\u80fd\u9700\u8981\u6383\u63cf\u6574\u500b\u8a02\u55ae\u8868\uff0c\u5c0e\u81f4\u5ef6\u9072\u3002<\/p>\n<p>\u901a\u904e\u5728\u8a02\u55ae\u8868\u7684\u7522\u54c1ID\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u67e5\u8a62\u6027\u80fd\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\uff1a<\/p>\n<pre><code>CREATE INDEX idx_product_id ON orders (product_id);<\/code><\/pre>\n<p>\u6b64\u5916\uff0c\u91cd\u5beb\u67e5\u8a62\u8a9e\u53e5\u4ee5\u4f7f\u7528\u806f\u63a5\u800c\u4e0d\u662f\u5b50\u67e5\u8a62\uff0c\u4e5f\u53ef\u4ee5\u9032\u4e00\u6b65\u63d0\u9ad8\u6027\u80fd\uff1a<\/p>\n<pre><code>SELECT o.* FROM orders o JOIN products p ON o.product_id = p.id WHERE p.name = '\u7279\u5b9a\u7522\u54c1';<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-fsWvaVoGCV\">\u7e3d\u7d50<\/h2>\n<p>\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5\u7684\u512a\u5316\u662f\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\u7684\u91cd\u8981\u624b\u6bb5\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528\u7d22\u5f15\u3001\u91cd\u5beb\u67e5\u8a62\u3001\u5229\u7528\u7de9\u5b58\u548c\u5206\u5340\u6280\u8853\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\u4f86\u8aaa\uff0c\u9019\u4e9b\u6280\u8853\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\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\u5e6b\u52a9\u60a8\u512a\u5316\u6578\u64da\u5eab\u6027\u80fd\uff0c\u63d0\u5347\u696d\u52d9\u6548\u7387\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22\u6578\u64da\u5eab\u67e5\u8a62\u7b97\u6cd5\u7684\u512a\u5316\u89e3\u6c7a\u65b9\u6848\uff0c\u63d0\u9ad8\u6578\u64da\u6aa2\u7d22\u6548\u7387\uff0c\u63d0\u5347\u7cfb\u7d71\u6027\u80fd\uff0c\u5be6\u73fe\u66f4\u5feb\u7684\u6578\u64da\u8655\u7406\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-186258","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186258","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=186258"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186258\/revisions"}],"predecessor-version":[{"id":186259,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186258\/revisions\/186259"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=186258"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=186258"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=186258"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}