{"id":28087,"date":"2024-11-24T16:44:21","date_gmt":"2024-11-24T08:44:21","guid":{"rendered":"https:\/\/fwq.ai\/blog\/28087\/"},"modified":"2024-11-24T16:44:21","modified_gmt":"2024-11-24T08:44:21","slug":"explain-%e4%b8%ad%e7%9a%84-extra-%e5%ad%97%e6%ae%b5%e5%a6%82%e4%bd%95%e5%88%a4%e6%96%ad%e4%ba%8c%e7%ba%a7%e7%b4%a2%e5%bc%95%e6%98%af%e5%90%a6%e6%b6%88%e9%99%a4%e5%9b%9e%e8%a1%a8%e6%93%8d%e4%bd%9c-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/28087\/","title":{"rendered":"Explain \u4e2d\u7684 Extra \u5b57\u6bb5\u5982\u4f55\u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u56de\u8868\u64cd\u4f5c\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/173139410832358.jpg\" class=\"aligncenter\" title=\"Explain \u4e2d\u7684 Extra \u5b57\u6bb5\u5982\u4f55\u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u56de\u8868\u64cd\u4f5c\uff1f\u63d2\u56fe\" alt=\"Explain \u4e2d\u7684 Extra \u5b57\u6bb5\u5982\u4f55\u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u56de\u8868\u64cd\u4f5c\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u901a\u8fc7 expln \u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u56de\u8868\u64cd\u4f5c<\/strong><\/p>\n<p><strong>\u5206\u6790\uff1a<\/strong><\/p>\n<p>\u7ed9\u5b9a\u7684 SQL \u67e5\u8be2\u5728 idx_track_source_id_created_at_len_parse_result_list \u7d22\u5f15\u4e0a\u4f7f\u7528\u4e86\u7d22\u5f15\u67e5\u627e\u3002\u8981\u5224\u65ad\u662f\u5426\u8fd8\u5b58\u5728\u56de\u8868\u64cd\u4f5c\uff0c\u9700\u8981\u68c0\u67e5 Extra \u5b57\u6bb5\u3002<\/p>\n<p><strong>\u5224\u65ad\u6807\u51c6\uff1a<\/strong><\/p>\n<ul>\n<li>\u5982\u679c Extra \u4e2d\u5305\u542b Using Index \u6216 Using Index Condition\uff0c\u5219\u4e0d\u9700\u8981\u56de\u8868\u3002<\/li>\n<li>\u5982\u679c Extra \u4e2d\u5305\u542b Using where \u4e14\u672a\u51fa\u73b0 Using Index\uff0c\u5219\u5b58\u5728\u56de\u8868\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<p><strong>\u672c\u4f8b\u5206\u6790\uff1a<\/strong><\/p>\n<p>\u7ed9\u5b9a explain \u7ed3\u679c\u4e2d\uff0cExtra \u5b57\u6bb5\u4e3a Using where; Using index; Using temporary; Using filesort\uff0c\u5176\u4e2d\uff1a<\/p>\n<ul>\n<li>Using index \u8868\u660e\u4f7f\u7528\u4e86\u7d22\u5f15\u67e5\u627e\u3002<\/li>\n<li>Using where \u8868\u660e\u9700\u8981\u6839\u636e WHERE \u6761\u4ef6\u8fc7\u6ee4\u7ed3\u679c\u3002<\/li>\n<\/ul>\n<p>\u56e0\u6b64\uff0c\u672c\u793a\u4f8b\u4e2d\u5b58\u5728\u56de\u8868\u64cd\u4f5c\u3002\u8fd9\u662f\u56e0\u4e3a\u7d22\u5f15\u8986\u76d6\u4e86\u6240\u9700\u5b57\u6bb5\uff0c\u4f46\u540c\u65f6\u4e5f\u9700\u8981\u6839\u636e WHERE \u6761\u4ef6\u8fc7\u6ee4\u6570\u636e\u3002\u56e0\u6b64\uff0cMySQL \u9700\u8981\u4ece\u805a\u7c07\u7d22\u5f15\u4e2d\u68c0\u7d22\u6ee1\u8db3\u6761\u4ef6\u7684\u884c\u3002<\/p>\n<p><strong>\u7ed3\u8bba\uff1a<\/strong><\/p>\n<p>\u901a\u8fc7\u68c0\u67e5 explain \u8f93\u51fa\u4e2d\u7684 Extra \u5b57\u6bb5\uff0c\u53ef\u4ee5\u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u4e86\u56de\u8868\u64cd\u4f5c\u3002\u5982\u679c Extra \u4e2d\u5305\u542b Using Index \u6216 Using Index Condition\uff0c\u5219\u4e0d\u9700\u8981\u56de\u8868\uff1b\u5426\u5219\uff0c\u5b58\u5728\u56de\u8868\u64cd\u4f5c\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fExpln \u4e2d\u7684 Extra \u5b57\u6bb5\u5982\u4f55\u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u56de\u8868\u64cd\u4f5c\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u901a\u8fc7 expln \u5224\u65ad\u4e8c\u7ea7\u7d22\u5f15\u662f\u5426\u6d88\u9664\u56de\u8868\u64cd\u4f5c \u5206\u6790\uff1a \u7ed9\u5b9a\u7684 SQL \u67e5\u8be2\u5728 idx_track_source_id_created_at_len_parse_result_list \u7d22\u5f15\u4e0a\u4f7f\u7528\u4e86\u7d22\u5f15\u67e5\u627e\u3002\u8981\u5224\u65ad\u662f\u5426\u8fd8\u5b58\u5728\u56de\u8868\u64cd\u4f5c\uff0c\u9700\u8981\u68c0\u67e5 Extra \u5b57\u6bb5\u3002 \u5224\u65ad\u6807\u51c6\uff1a \u5982\u679c Extra \u4e2d\u5305\u542b Using Index \u6216 Using Index Condition\uff0c\u5219\u4e0d\u9700\u8981\u56de\u8868\u3002 \u5982\u679c Extra \u4e2d\u5305\u542b Using where \u4e14\u672a\u51fa\u73b0 Using Index\uff0c\u5219\u5b58\u5728\u56de\u8868\u64cd\u4f5c\u3002 \u672c\u4f8b\u5206\u6790\uff1a \u7ed9\u5b9a explain \u7ed3\u679c\u4e2d\uff0cExtra \u5b57\u6bb5\u4e3a Using where; Using index; Using temporary; Using filesort\uff0c\u5176\u4e2d\uff1a Using index \u8868\u660e\u4f7f\u7528\u4e86\u7d22\u5f15\u67e5\u627e\u3002 Using where \u8868\u660e\u9700\u8981\u6839\u636e WHERE \u6761\u4ef6\u8fc7\u6ee4\u7ed3\u679c\u3002 \u56e0\u6b64\uff0c\u672c\u793a\u4f8b\u4e2d\u5b58\u5728\u56de\u8868\u64cd\u4f5c\u3002\u8fd9\u662f\u56e0\u4e3a\u7d22\u5f15\u8986\u76d6\u4e86\u6240\u9700\u5b57\u6bb5\uff0c\u4f46\u540c\u65f6\u4e5f\u9700\u8981\u6839\u636e WHERE \u6761\u4ef6\u8fc7\u6ee4\u6570\u636e\u3002\u56e0\u6b64\uff0cMySQL \u9700\u8981\u4ece\u805a\u7c07\u7d22\u5f15\u4e2d\u68c0\u7d22\u6ee1\u8db3\u6761\u4ef6\u7684\u884c\u3002 \u7ed3\u8bba\uff1a [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-28087","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/28087","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=28087"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/28087\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=28087"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=28087"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=28087"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}