{"id":200978,"date":"2025-05-06T12:49:52","date_gmt":"2025-05-06T04:49:52","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200978\/"},"modified":"2025-05-06T12:49:52","modified_gmt":"2025-05-06T04:49:52","slug":"explain-%e6%98%be%e7%a4%ba-using-temporary-using-filesort%ef%bc%8c%e8%bf%99%e6%98%af%e5%90%a6%e6%84%8f%e5%91%b3%e7%9d%80%e6%9f%a5%e8%af%a2%e9%9c%80%e8%a6%81%e5%9b%9e%e8%a1%a8%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200978\/","title":{"rendered":"EXPLAIN \u663e\u793a &#8220;Using temporary; Using filesort&#8221;\uff0c\u8fd9\u662f\u5426\u610f\u5473\u7740\u67e5\u8be2\u9700\u8981\u56de\u8868\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>EXPLAIN \u663e\u793a &#8220;Using temporary; Using filesort&#8221;\uff0c\u8fd9\u662f\u5426\u610f\u5473\u7740\u67e5\u8be2\u9700\u8981\u56de\u8868\uff1f<\/h1>\n<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241123\/17323738606741ed64940d5.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u901a\u8fc7 EXPLAIN \u5224\u65ad\u67e5\u8be2\u662f\u5426\u56de\u8868<\/strong><\/p>\n<p>\u8981\u5224\u65ad\u67e5\u8be2\u662f\u5426\u5b58\u5728\u56de\u8868\u64cd\u4f5c\uff0c\u53ef\u4ee5\u4f7f\u7528 EXPLAIN \u5206\u6790\u67e5\u8be2\u8ba1\u5212\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u901a\u8fc7 EXPLAIN \u8f93\u51fa\u7684 Extra \u5b57\u6bb5\u5224\u65ad\uff1a<\/p>\n<ul>\n<li><strong>Using Index\uff1a<\/strong>\u8868\u793a\u51fa\u73b0\u7d22\u5f15\u8986\u76d6\uff0c\u67e5\u8be2\u6240\u9700\u7684\u5b57\u6bb5\u90fd\u5728\u7d22\u5f15\u4e2d\uff0c\u4e0d\u9700\u8981\u56de\u8868\u3002<\/li>\n<li><strong>Using Index Condition\uff1a<\/strong>\u8868\u793a\u4f7f\u7528\u4e86\u7d22\u5f15\u67e5\u627e\uff0c\u4f46\u9700\u8981\u8fc7\u6ee4\uff0c\u56e0\u4e3a\u8981\u8fc7\u6ee4\u7684\u5b57\u6bb5\u4e0d\u5728\u7d22\u5f15\u4e2d\u3002\u4e0d\u56de\u8868\u3002<\/li>\n<li><strong>Using Index &amp; Using where\uff1a<\/strong>\u8868\u793a\u7d22\u5f15\u4e2d\u53ef\u4ee5\u627e\u5230select\u7684\u6570\u636e\uff0c\u4f46\u9700\u8981\u6839\u636ewhere\u6761\u4ef6\u8fc7\u6ee4\u3002\u4e0d\u56de\u8868\u3002<\/li>\n<li><strong>Using where\uff1a<\/strong>\u5728\u4f7f\u7528\u5230\u4e86\u7d22\u5f15\u7684\u60c5\u51b5\u4e0b\uff0cExtra\u662fUsing where\uff0c\u8868\u793a\u56de\u8868\u67e5\u8be2\u6570\u636e\u3002<\/li>\n<li><strong>\u4e3b\u952e\u67e5\u8be2\uff1a<\/strong>\u4e0d\u56de\u8868\uff0c\u56e0\u4e3a\u8981\u627e\u7684\u5b57\u6bb5\u4ece\u805a\u7c07\u7d22\u5f15\u4e0a\u76f4\u63a5\u67e5\u627e\uff0c\u4e0d\u9700\u8981\u56de\u8868\u3002\u4f46\u662f Extra \u65e0\u6cd5\u53cd\u6620\u8fd9\u4e00\u70b9\u3002<\/li>\n<\/ul>\n<p>\u7ed3\u5408\u4f60\u7684\u95ee\u9898\uff0cEXPLAIN \u8f93\u51fa\u663e\u793a\uff1aUsing temporary; Using filesort\uff0c\u8fd9\u610f\u5473\u7740\u4f7f\u7528\u4e86\u4e34\u65f6\u8868\u548c\u6587\u4ef6\u6392\u5e8f\uff0c\u9700\u8981\u56de\u8868\u3002\u56e0\u6b64\uff0c\u8be5\u67e5\u8be2\u5b58\u5728\u56de\u8868\u64cd\u4f5c\u3002<\/p>\n<p>\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aEXPLAIN \u663e\u793a &#8220;Using temporary; Using filesort&#8221;\uff0c\u8fd9\u662f\u5426\u610f\u5473\u7740\u67e5\u8be2\u9700\u8981\u56de\u8868\uff1f\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6570\u636e\u5e93\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>EXPLAIN \u663e\u793a &#038;#822&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200978","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200978","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200978"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200978\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}