{"id":1941,"date":"2020-07-29T21:23:51","date_gmt":"2020-07-29T13:23:51","guid":{"rendered":"http:\/\/39.97.231.10\/?p=1941"},"modified":"2020-07-29T21:23:51","modified_gmt":"2020-07-29T13:23:51","slug":"mysql%e5%a6%82%e4%bd%95%e9%81%bf%e5%85%8d%e5%85%a8%e8%a1%a8%e6%89%ab%e6%8f%8f","status":"publish","type":"post","link":"http:\/\/www.weijing.co\/?p=1941","title":{"rendered":"MySQL\u5982\u4f55\u907f\u514d\u5168\u8868\u626b\u63cf"},"content":{"rendered":"
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\nMySQL\u5168\u8868\u626b\u63cf\u5728\u5927\u591a\u6570\u573a\u666f\u4e0b\u6027\u80fd\u90fd\u662f\u975e\u5e38\u4f4e\u4e0b\u7684\uff0c\u5c24\u5176\u5728\u8868\u6570\u636e\u91cf\u7279\u522b\u5927\u7684\u60c5\u51b5\u4e0b\uff0c\u5168\u8868\u626b\u63cf\u4f1a\u8017\u5c3d\u6570\u636e\u5e93\u8d44\u6e90\uff0c\u4e25\u91cd\u65f6\u4f1a\u5bfc\u81f4\u6570\u636e\u5e93\u670d\u52a1\u4e0d\u53ef\u7528\uff0c\u6570\u636e\u5e93\u5d29\u6e83\uff0c\u56e0\u6b64\uff0c\u4e1a\u52a1SQL\u5728\u53d1\u5e03\u4e0a\u7ebf\u524d\uff0c\u5e94\u5f53\u68c0\u67e5\u662f\u5426\u4f1a\u5bfc\u81f4\u5168\u8868\u626b\u63cf\u3002<\/p>\n

1. MySQL\u5168\u8868\u626b\u63cf\u7684\u539f\u56e0<\/h4>\n

\u901a\u8fc7\u5bf9SQL\u6267\u884cexplain\uff0c\u5728\u8f93\u51fa\u4fe1\u606f\u4e2d\u5982\u679ctype\u5b57\u6bb5\u4e3aAll\uff0c\u90a3\u4e48\u8fd9\u4e2aSQL\u5c31\u662f\u8d70\u7684\u5168\u8868\u626b\u63cf\u3002\u5168\u8868\u626b\u63cf\u901a\u5e38\u7531\u4ee5\u4e0b\u539f\u56e0\u4ea7\u751f\uff1a<\/p>\n

    \n
  1. \u8868\u975e\u5e38\u5c0f\uff0c\u5168\u8868\u626b\u63cf\u6bd4\u8d70\u7d22\u5f15\u6709\u66f4\u597d\u7684\u6027\u80fd\u3002\u901a\u5e38\u8fd9\u6837\u7684\u8868\u8bb0\u5f55\u6570\u5c0f\u4e8e10\uff0c\u5e76\u4e14\u6bcf\u884c\u8bb0\u5f55\u7684\u6570\u636e\u91cf\u4e5f\u4e0d\u5927\u3002<\/li>\n
  2. \u5728where\u6216\u8005on\u5b50\u53e5\u4e0a\u6d89\u53ca\u5230\u7684\u5b57\u6bb5\uff0c\u6ca1\u6709\u53ef\u7528\u7684\u7d22\u5f15\u3002<\/li>\n
  3. \u901a\u8fc7\u7d22\u5f15\u5b57\u6bb5\u4e0e\u5e38\u6570\u503c\u8fdb\u884c\u6761\u4ef6\u5339\u914d\uff0cMySQL\u4f18\u5316\u5668\u57fa\u4e8e\u7d22\u5f15\u8ba1\u7b97\u51fa\u626b\u63cf\u7684\u8bb0\u5f55\u6570\u592a\u591a\uff0c\u8d85\u8fc7\u5168\u8868\u8bb0\u5f55\u768430%\uff0c\u4f18\u5316\u5668\u8ba4\u4e3a\u5168\u8868\u626b\u63cf\u6027\u80fd\u5c06\u6bd4\u8d70\u7d22\u5f15\u66f4\u597d\u3002<\/li>\n
  4. \u5728\u4e00\u4e2a\u533a\u5206\u5ea6\u4e0d\u597d\u7684\u5b57\u6bb5\u4e0a\u5efa\u7d22\u5f15\uff0c\u6bd4\u5982\u6027\u522b\uff0c\u67e5\u8be2\u7537\u6027\u6216\u8005\u5973\u6027\uff0c\u5373\u4f7f\u5728\u6027\u522b\u5b57\u6bb5\u4e0a\u5efa\u7d22\u5f15\uff0c\u4f18\u5316\u5668\u8ba4\u4e3a\u8d70\u7d22\u5f15\u6027\u80fd\u5e76\u4e0d\u5982\u5168\u8868\u626b\u63cf\u597d\u3002<\/li>\n<\/ol>\n

    \u5bf9\u4e8e\u8bb0\u5f55\u6570\u6bd4\u8f83\u5c0f\u7684\u8868\uff0c\u5168\u8868\u626b\u63cf\u5e76\u4e0d\u4f1a\u5bf9\u6027\u80fd\u4ea7\u751f\u592a\u5927\u7684\u5f71\u54cd\uff0c\u6709\u65f6\u5019\u53cd\u800c\u4f1a\u63d0\u9ad8\u6027\u80fd\u3002\u4f46\u662f\u968f\u7740\u6570\u636e\u91cf\u7684\u589e\u52a0\uff0c\u5168\u8868\u626b\u63cf\u4f1a\u8d8a\u6765\u8d8a\u6162\uff0c\u56e0\u6b64\u5e94\u5f53\u5c3d\u53ef\u80fd\u7684\u907f\u514d\u5168\u8868\u626b\u63cf\u3002<\/p>\n

    2. MySQL\u5982\u4f55\u907f\u514d\u5168\u8868\u626b\u63cf<\/h4>\n

    \u6709\u4e00\u4e9b\u65b9\u5f0f\u53ef\u4ee5\u5e2e\u52a9\u4f18\u5316\u5668\u907f\u514d\u4f7f\u7528\u5168\u8868\u626b\u63cf\uff0c\u5982\u4e0b\uff1a<\/p>\n

      \n
    1. \u5728where\u6761\u4ef6\u6216\u8005join\u7684\u8fde\u63a5\u5b57\u6bb5\u4e0a\u6dfb\u52a0\u5408\u9002\u7684\u7d22\u5f15\uff0c\u5927\u591a\u6570\u5168\u8868\u626b\u63cf\u662f\u7531\u4e8e\u5fd8\u4e86\u52a0\u7d22\u5f15\u5bfc\u81f4\u3002<\/li>\n
    2. ANALYZE TABLE\u00a0tbl_name\uff0c\u66f4\u65b0\u7d22\u5f15\u5206\u5e03\u7edf\u8ba1\u4fe1\u606f\uff0c\u5e2e\u52a9\u4f18\u5316\u5668\u66f4\u51c6\u786e\u5730\u8bc4\u4f30\u6267\u884c\u6210\u672c\uff0c\u4ea7\u751f\u66f4\u4f18\u7684\u6267\u884c\u8ba1\u5212\u3002<\/li>\n
    3. FORCE INDEX\uff0c\u8ba9MySQL\u4f18\u5316\u5668\u5f3a\u5236\u8d70\u67d0\u4e2a\u7d22\u5f15\u3002<\/li>\n
    4. \u8bbe\u7f6e\u53c2\u6570–max-seeks-for-key=1000\u00a0\u6216\u8005\u00a0SET max_seeks_for_key=1000\uff0c\u8fd9\u4e2a\u503c\u8bbe\u7f6e\u7684\u8d8a\u5c0f\uff0cMySQL\u4f18\u5316\u5668\u8d8a\u503e\u5411\u4e8e\u8d70\u7d22\u5f15\uff0c\u800c\u4e0d\u662f\u5168\u8868\u626b\u63cf\u3002<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

      MySQL\u5168\u8868\u626b\u63cf\u5728\u5927\u591a\u6570\u573a\u666f\u4e0b\u6027\u80fd\u90fd\u662f\u975e\u5e38\u4f4e\u4e0b\u7684\uff0c\u5c24\u5176\u5728\u8868\u6570\u636e\u91cf\u7279\u522b\u5927\u7684\u60c5\u51b5\u4e0b\uff0c\u5168\u8868\u626b\u63cf\u4f1a\u8017\u5c3d\u6570\u636e\u5e93\u8d44\u6e90\uff0c\u4e25 …<\/p>\n

      MySQL\u5982\u4f55\u907f\u514d\u5168\u8868\u626b\u63cf<\/span> \u67e5\u770b\u5168\u6587 »<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":""},"categories":[90,88],"tags":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"mailpoet_newsletter_max":false,"woocommerce_thumbnail":false,"woocommerce_single":false,"woocommerce_gallery_thumbnail":false,"shop_catalog":false,"shop_single":false,"shop_thumbnail":false},"uagb_author_info":{"display_name":"weijing","author_link":"http:\/\/www.weijing.co\/?author=4"},"uagb_comment_info":0,"uagb_excerpt":"MySQL\u5168\u8868\u626b\u63cf\u5728\u5927\u591a\u6570\u573a\u666f\u4e0b\u6027\u80fd\u90fd\u662f\u975e\u5e38\u4f4e\u4e0b\u7684\uff0c\u5c24\u5176\u5728\u8868\u6570\u636e\u91cf\u7279\u522b\u5927\u7684\u60c5\u51b5\u4e0b\uff0c\u5168\u8868\u626b\u63cf\u4f1a\u8017\u5c3d\u6570\u636e\u5e93\u8d44\u6e90\uff0c\u4e25…","_links":{"self":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1941"}],"collection":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1941"}],"version-history":[{"count":0,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1941\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1941"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1941"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1941"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}