{"id":1539,"date":"2017-08-18T22:43:04","date_gmt":"2017-08-18T14:43:04","guid":{"rendered":"http:\/\/coderbee.net\/?p=1539"},"modified":"2020-08-27T16:14:19","modified_gmt":"2020-08-27T08:14:19","slug":"mysql-%e9%ab%98%e6%80%a7%e8%83%bd%e7%9a%84%e7%b4%a2%e5%bc%95%e7%ad%96%e7%95%a5","status":"publish","type":"post","link":"https:\/\/coderbee.net\/index.php\/db\/20170818\/1539","title":{"rendered":"MySQL \u9ad8\u6027\u80fd\u7684\u7d22\u5f15\u7b56\u7565"},"content":{"rendered":"<p>\u91cd\u65b0\u770b\u4e86\u4e00\u904d\u505a\u5f97\u8bb0\u5f55\u3002<\/p>\n<h1>\u72ec\u7acb\u7684\u5217<\/h1>\n<p>\u7d22\u5f15\u5217\u4e0d\u80fd\u662f\u8868\u8fbe\u5f0f\u7684\u4e00\u90e8\u5206\uff0c\u4e5f\u4e0d\u80fd\u662f\u51fd\u6570\u7684\u53c2\u6570\u3002\u5728 where \u8bed\u53e5\u91cc\uff0c\u59cb\u7ec8\u5c06\u7d22\u5f15\u5217\u5355\u72ec\u653e\u5728\u6bd4\u8f83\u7b26\u53f7\u7684\u4e00\u4fa7\u3002<\/p>\n<h1>\u524d\u7f00\u7d22\u5f15\u548c\u7d22\u5f15\u7684\u9009\u62e9\u6027<\/h1>\n<p>\u9009\u62e9\u6027\u662f\u6307\u4e0d\u91cd\u590d\u7684\u7d22\u5f15\u503c\u548c\u6570\u636e\u8868\u7684\u8bb0\u5f55\u603b\u6570\u7684\u6bd4\u503c\u3002<br \/>\n\u9009\u62e9\u6027\u8d8a\u9ad8\u67e5\u8be2\u6548\u7387\u8d8a\u9ad8\uff0c\u552f\u4e00\u7d22\u5f15\u7684\u9009\u62e9\u6027\u662f 1\u3002<\/p>\n<p>\u5bf9\u4e8e\u5f88\u957f\u7684\u7d22\u5f15\u5217\uff0c\u5224\u65ad\u5b83\u7684\u524d\u7f00\u662f\u5426\u6709\u8db3\u591f\u7684\u9009\u62e9\u6027\u3002<br \/>\nMySQL \u65e0\u6cd5\u7528\u524d\u7f00\u7d22\u5f15\u505a <code>order by<\/code> \u548c <code>group by<\/code> \uff0c\u4e5f\u65e0\u6cd5\u7528\u524d\u7f00\u7d22\u5f15\u505a\u8986\u76d6\u626b\u63cf\u3002<\/p>\n<h1>\u591a\u5217\u7d22\u5f15<\/h1>\n<p>MySQL 5.0 \u5f15\u5165\u7d22\u5f15\u5408\u5e76\u7b56\u7565\u3002\u7d22\u5f15\u5408\u5e76\u4f7f\u7528\u7684\u8303\u56f4\uff1a OR \u6761\u4ef6\u7684\u8054\u5408\uff0cAND \u6761\u4ef6\u7684\u76f8\u4ea4\uff0c\u7ec4\u5408\u524d\u4e24\u79cd\u6761\u4ef6\u7684\u7ec4\u5408\u548c\u76f8\u4ea4\u3002<br \/>\n\u7d22\u5f15\u5408\u5e76\u6697\u793a\u7740\u4e0d\u826f\u7684\u8bbe\u8ba1\uff0c\u53ef\u4ee5\u8003\u8651\u7ec4\u5408\u7d22\u5f15\u3002<\/p>\n<h1>\u7d22\u5f15\u5217\u987a\u5e8f<\/h1>\n<p>\u6b63\u786e\u7684\u987a\u5e8f\u4f9d\u8d56\u4e8e\u4f7f\u7528\u8be5\u7d22\u5f15\u7684\u67e5\u8be2\uff0c\u5e76\u4e14\u540c\u65f6\u9700\u8981\u8003\u8651\u5982\u4f55\u66f4\u597d\u5730\u6ee1\u8db3\u6392\u5e8f\u548c\u5206\u7ec4\u7684\u9700\u8981\u3002<\/p>\n<p>\u5c06\u9009\u62e9\u6027\u9ad8\u7684\u5217\u653e\u5728\u6700\u524d\u5217\uff0c\u901a\u5e38\u4e0d\u5982\u907f\u514d\u968f\u673a I\/O \u548c\u6392\u5e8f\u91cd\u8981\u3002<br \/>\n\u4e0d\u9700\u8981\u8003\u8651\u6392\u5e8f\u3001\u5206\u7ec4\u65f6\uff0c\u5e94\u5c06\u9009\u62e9\u6027\u6700\u9ad8\u7684\u5217\u653e\u5728\u6700\u524d\u9762\u3002<\/p>\n<p>\u6027\u80fd\u4e0d\u53ea\u662f\u4f9d\u8d56\u4e8e\u6240\u6709\u7d22\u5f15\u7684\u5217\u7684\u9009\u62e9\u6027\uff0c\u4e5f\u548c\u67e5\u8be2\u6761\u4ef6\u7684\u5177\u4f53\u503c\u6709\u5173\uff0c\u4e5f\u5c31\u662f\u548c\u503c\u7684\u5206\u5e03\u6709\u5173\u3002<\/p>\n<p><!--more--><\/p>\n<h1>\u805a\u65cf\u7d22\u5f15<\/h1>\n<p>\u805a\u65cf\u7d22\u5f15\u4e0d\u662f\u7d22\u5f15\u7684\u4e00\u79cd\u7c7b\u578b\uff0c\u800c\u662f\u4e00\u79cd\u6570\u636e\u5b58\u50a8\u683c\u5f0f\u3002\uff08\u7c7b\u4f3c Oracle \u7684\u7d22\u5f15\u7ec4\u7ec7\u8868\uff09<\/p>\n<p>\u8868\u6709\u805a\u65cf\u7d22\u5f15\u65f6\uff0c\u5b83\u7684\u6570\u636e\u884c\u5b9e\u9645\u4e0a\u5b58\u653e\u5728\u7d22\u5f15\u7684\u53f6\u5b50\u9875\u4e2d\u3002<\/p>\n<p>InnoDB \u901a\u8fc7\u4e3b\u952e\u805a\u96c6\u6570\u636e\u3002\u5982\u679c\u6ca1\u6709\u4e3b\u952e\uff0c\u5219\u9009\u62e9\u4e00\u4e2a\u552f\u4e00\u7684\u975e\u7a7a\u7d22\u5f15\u4ee3\u66ff\uff0c\u5982\u679c\u6ca1\u6709\u8fd9\u6837\u7684\u7d22\u5f15\uff0cInnoDB \u4f1a\u9690\u5f0f\u5b9a\u4e49\u4e00\u4e2a\u4e3b\u952e\u6765\u4f5c\u4e3a\u805a\u65cf\u7d22\u5f15\u3002<\/p>\n<p>InnoDB \u53ea\u805a\u96c6\u5728\u540c\u4e00\u4e2a\u9875\u9762\u4e2d\u7684\u6570\u636e\uff0c\u5305\u542b\u76f8\u90bb\u952e\u503c\u7684\u9875\u9762\u53ef\u80fd\u76f8\u8ddd\u751a\u8fdc\uff08\u7269\u7406\u4e0d\u76f8\u90bb\uff09\u3002<\/p>\n<h2>\u805a\u65cf\u7d22\u5f15\u7684\u4f18\u7f3a\u70b9<\/h2>\n<p>\u4f18\u70b9\uff1a<\/p>\n<ul>\n<li>\u628a\u76f8\u5173\u6570\u636e\u4fdd\u5b58\u5728\u4e00\u8d77\u3002<\/li>\n<li>\u6570\u636e\u8bbf\u95ee\u5feb\u3002\u805a\u65cf\u7d22\u5f15\u5c06\u7d22\u5f15\u548c\u6570\u636e\u4fdd\u5b58\u5728\u540c\u4e00\u4e2a B-Tree \u4e2d\uff0c\u56e0\u6b64\u4ece\u805a\u65cf\u7d22\u5f15\u4e2d\u83b7\u53d6\u6570\u636e\u901a\u5e38\u6bd4\u5728\u975e\u805a\u65cf\u7d22\u5f15\u4e2d\u67e5\u627e\u8981\u5feb\u3002<\/li>\n<li>\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\u626b\u63cf\u7684\u67e5\u8be2\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u9875\u8282\u70b9\u4e2d\u7684\u4e3b\u952e\u503c\u3002<\/li>\n<\/ul>\n<p>\u7f3a\u70b9\uff1a<\/p>\n<ul>\n<li>\u805a\u65cf\u6570\u636e\u6700\u5927\u9650\u5ea6\u63d0\u9ad8\u4e86 I\/O \u5bc6\u96c6\u578b\u5e94\u7528\u7684\u6027\u80fd\uff0c\u4f46\u5982\u679c\u6570\u636e\u90fd\u5728\u5185\u5b58\u4e2d\uff0c\u5219\u6ca1\u6709\u8fd9\u4e2a\u4f18\u52bf\u3002<\/li>\n<li>\u63d2\u5165\u901f\u5ea6\u4f9d\u8d56\u63d2\u5165\u987a\u5e8f\u3002\u6309\u7167\u4e3b\u952e\u7684\u987a\u5e8f\u63d2\u5165 \u662f\u52a0\u8f7d\u6570\u636e\u5230 InnoDB \u8868\u4e2d\u901f\u5ea6\u6700\u5feb\u7684\u65b9\u5f0f\u3002\u5982\u679c\u4e0d\u662f\u6309\u4e3b\u952e\u987a\u5e8f\u52a0\u8f7d\u7684\uff0c\u52a0\u8f7d\u5b8c\u6210\u540e\u6700\u597d\u4f7f\u7528 <code>optimize table<\/code> \u547d\u4ee4\u91cd\u65b0\u7ec4\u7ec7\u4e0b\u8868\u3002<\/li>\n<li>\u66f4\u65b0\u805a\u65cf\u7d22\u5f15\u7684\u4ee3\u4ef7\u5f88\u9ad8\uff0c\u56e0\u4e3a\u4f1a\u5f3a\u5236 InnoDB \u5c06\u6bcf\u4e2a\u88ab\u66f4\u65b0\u7684\u884c\u79fb\u52a8\u5230\u65b0\u7684\u4f4d\u7f6e\u3002<\/li>\n<li>\u57fa\u4e8e\u805a\u65cf\u7d22\u5f15\u7684\u8868\u5728\u63d2\u5165\u65b0\u884c\uff0c\u6216\u8005\u4e3b\u952e\u88ab\u66f4\u65b0\u5bfc\u81f4\u9700\u8981\u79fb\u52a8\u884c\u7684\u65f6\u5019\uff0c\u53ef\u80fd\u9762\u4e34\u201c\u9875\u5206\u88c2(page split)\u201d\u7684\u95ee\u9898\u3002\u9875\u5206\u88c2\u4f1a\u5bfc\u81f4\u8868\u5360\u7528\u66f4\u591a\u7684\u78c1\u76d8\u7a7a\u95f4\u3002<\/li>\n<li>\u805a\u65cf\u7d22\u5f15\u53ef\u80fd\u5bfc\u81f4\u5168\u8868\u626b\u63cf\u4f1a\u53d8\u6162\uff0c\u5c24\u5176\u662f\u884c\u6bd4\u8f83\u7a00\u758f\uff0c\u6216\u8005\u7531\u4e8e\u9875\u5206\u88c2\u5bfc\u81f4\u6570\u636e\u5b58\u50a8\u4e0d\u8fde\u7eed\u7684\u65f6\u5019\u3002<\/li>\n<li>\u4e8c\u7ea7\u7d22\u5f15\uff08\u975e\u805a\u65cf\u7d22\u5f15\uff09\u53ef\u80fd\u6bd4\u60f3\u8c61\u4e2d\u7684\u8981\u5927\uff0c\u56e0\u4e3a\u5728\u4e8c\u7ea7\u7d22\u5f15\u7684\u53f6\u5b50\u8282\u70b9\u4e5f\u5305\u542b\u4e86\u5f15\u7528\u884c\u7684\u4e3b\u952e\u5217\u3002<\/li>\n<li>\u4e8c\u7ea7\u7d22\u5f15\u8bbf\u95ee\u9700\u8981\u4e24\u6b21\u7684\u7d22\u5f15\u67e5\u627e\uff0c\u800c\u4e0d\u662f\u4e00\u6b21\u3002\uff08\u4e8c\u7ea7\u7d22\u5f15\u4fdd\u5b58\u7684\u4e0d\u662f\u6307\u5411\u884c\u7684\u7269\u7406\u4f4d\u7f6e\u7684\u6307\u9488\uff0c\u800c\u662f\u884c\u7684\u4e3b\u952e\u503c\u3002\u56e0\u6b64\u662f\u73b0\u5728\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u627e\u5230\u4e3b\u952e\u503c\uff0c\u7136\u540e\u7528\u4e3b\u952e\u503c\u5728\u805a\u65cf\u7d22\u5f15\u4e2d\u67e5\u627e\u3002\uff09 \u8fd9\u6837\u7684\u7b56\u7565\u51cf\u5c11\u4e86\u5f53\u51fa\u73b0\u884c\u79fb\u52a8\u6216\u8005\u6570\u636e\u9875\u5206\u88c2\u65f6\u4e8c\u7ea7\u7d22\u5f15\u7684\u7ef4\u62a4\u5de5\u4f5c\u3002<\/li>\n<\/ul>\n<p>\u4f7f\u7528 InnoDB \u65f6\u5e94\u8be5\u5c3d\u53ef\u80fd\u5730\u6309\u4e3b\u952e\u7684\u987a\u5e8f\u63d2\u5165\u6570\u636e\uff0c\u5e76\u4e14\u5c3d\u53ef\u80fd\u5730\u4f7f\u7528\u5355\u8c03\u9012\u589e\u52a0\u7684\u503c\u6765\u63d2\u5165\u65b0\u884c\u3002\u6700\u597d\u907f\u514d\u968f\u673a\u7684\uff08\u4e0d\u8fde\u7eed\u4e14\u503c\u7684\u5206\u5e03\u8303\u56f4\u975e\u5e38\u5927\uff0c\u6bd4\u5982 UUID\uff09\u805a\u65cf\u7d22\u5f15\uff0c\u7279\u522b\u662f\u5bf9\u4e8e I\/O \u5bc6\u96c6\u578b\u7684\u5e94\u7528\u3002<\/p>\n<p>\u4f7f\u7528\u968f\u673a\u4e3b\u952e\u53ef\u80fd\u5b58\u5728\u5982\u4e0b\u7f3a\u70b9\uff1a<\/p>\n<ul>\n<li>\u5199\u5165\u7684\u76ee\u6807\u9875\u53ef\u80fd\u5df2\u7ecf\u5237\u65b0\u5230\u78c1\u76d8\u4e0a\u5e76\u4e14\u4ece\u7f13\u5b58\u4e2d\u79fb\u9664\uff0c\u6216\u8005\u662f\u8fd8\u6ca1\u6709\u88ab\u52a0\u8f7d\u5230\u7f13\u5b58\u4e2d\uff0cInnoDB \u5728\u63d2\u5165\u4e4b\u524d\u4e0d\u5f97\u4e0d\u5148\u627e\u5230\u5e76\u4ece\u78c1\u76d8\u8bfb\u53d6\u76ee\u6807\u9875\u5230\u5185\u5b58\u4e2d\u3002\u8fd9\u5c06\u5bfc\u81f4\u5927\u91cf\u7684\u968f\u673a I\/O \u3002<\/li>\n<li>\u56e0\u4e3a\u5199\u5165\u662f\u4e71\u5e8f\u7684\uff0cInnoDB \u4e0d\u5f97\u4e0d\u9891\u7e41\u5730\u505a\u9875\u5206\u88c2\u64cd\u4f5c\uff0c\u4ee5\u4fbf\u4e3a\u65b0\u7684\u884c\u5206\u914d\u7a7a\u95f4\u3002\u9875\u5206\u88c2\u4f1a\u5bfc\u81f4\u79fb\u52a8\u5927\u91cf\u6570\u636e\uff0c\u4e00\u6b21\u63d2\u5165\u6700\u5c11\u9700\u8981\u4fee\u6539\u4e09\u4e2a\u9875\u9762\u800c\u4e0d\u662f\u4e00\u4e2a\u9875\u9762\u3002<\/li>\n<li>\u7531\u4e8e\u9891\u7e41\u7684\u9875\u5206\u88c2\uff0c\u9875\u4f1a\u53d8\u5f97\u7a00\u758f\u5e76\u88ab\u4e0d\u89c4\u5219\u5730\u586b\u5145\uff0c\u6700\u7ec8\u4f1a\u6709\u788e\u7247\u3002<\/li>\n<\/ul>\n<p>\u987a\u5e8f\u4e3b\u952e\u7684\u7f3a\u70b9\uff1a<\/p>\n<ul>\n<li>\u4e3b\u952e\u7684\u4e0a\u754c\u4f1a\u6210\u4e3a\u201c\u70ed\u70b9\u201d\u3002\u56e0\u4e3a\u6240\u6709\u7684\u63d2\u5165\u90fd\u53d1\u751f\u5728\u8fd9\u91cc\uff0c\u6240\u4ee5\u5e76\u53d1\u63d2\u5165\u53ef\u80fd\u5bfc\u81f4\u95f4\u9699\u9501\u7ade\u4e89\u3002<\/li>\n<li>\u53e6\u4e00\u4e2a\u70ed\u70b9\u53ef\u80fd\u662f <code>auto_increment<\/code> \u9501\u673a\u5236\u3002<\/li>\n<\/ul>\n<h1>\u8986\u76d6\u7d22\u5f15<\/h1>\n<p>\u5982\u679c\u4e00\u4e2a\u7d22\u5f15\u5305\u542b\u67e5\u8be2\u9700\u8981\u7684\u6240\u6709\u5b57\u6bb5\u7684\u503c\uff0c\u5c31\u79f0\u4e3a\u7d22\u5f15\u8986\u76d6\u3002\u8fd9\u6837\u53ea\u9700\u8981\u626b\u63cf\u7d22\u5f15\u65e0\u987b\u56de\u8868\u3002<\/p>\n<p>\u597d\u5904\uff1a<\/p>\n<ul>\n<li>\u7d22\u5f15\u6761\u76ee\u901a\u5e38\u8fdc\u5c0f\u4e8e\u6570\u636e\u884c\u7684\u5927\u5c0f\uff0c\u53ea\u8bfb\u53d6\u7d22\u5f15\u4f1a\u6781\u5927\u51cf\u5c11\u6570\u636e\u8bbf\u95ee\u91cf\u3002<\/li>\n<li>\u7d22\u5f15\u662f\u6309\u7167\u503c\u987a\u5e8f\u5b58\u50a8\u7684\uff08\u81f3\u5c11\u5355\u4e2a\u9875\u5185\u662f\u5982\u6b64\uff09\uff0c\u5bf9\u4e8e I\/O \u5bc6\u96c6\u578b\u7684\u8303\u56f4\u67e5\u8be2\u4f1a\u6bd4\u968f\u673a\u4ece\u78c1\u76d8\u8bfb\u53d6\u6bcf\u4e00\u884c\u6570\u636e\u7684 I\/O \u8981\u5c11\u5f97\u591a\u3002<\/li>\n<li>\u4e00\u4e9b\u5b58\u50a8\u5f15\u64ce\u5982 MyISAM \u5728\u5185\u5b58\u4e2d\u53ea\u7f13\u5b58\u7d22\u5f15\uff0c\u6570\u636e\u5219\u4f9d\u8d56\u4e8e\u64cd\u4f5c\u7cfb\u7edf\u6765\u7f13\u5b58\uff0c\u56e0\u6b64\u8981\u8bbf\u95ee\u6570\u636e\u9700\u8981\u4e00\u6b21\u7cfb\u7edf\u8c03\u7528\u3002\u8fd9\u53ef\u80fd\u4f1a\u5bfc\u81f4\u4e25\u91cd\u7684\u6027\u80fd\u95ee\u9898\uff0c\u7279\u522b\u662f\u90a3\u4e9b\u7cfb\u7edf\u8c03\u7528\u5360\u4e86\u6570\u636e\u8bbf\u95ee\u7684\u6700\u5927\u5f00\u9500\u7684\u573a\u666f\u3002<\/li>\n<li>\u7531\u4e8e InnoDB \u7684\u805a\u65cf\u7d22\u5f15\uff0c\u8986\u76d6\u7d22\u5f15\u5bf9 InnoDB \u8868\u7279\u522b\u6709\u7528\u3002InnoDB \u7684\u4e8c\u7ea7\u7d22\u5f15\u5728\u53f6\u5b50\u8282\u70b9\u4e2d\u4fdd\u5b58\u4e86\u884c\u7684\u4e3b\u952e\u503c\uff0c\u6240\u4ee5\u5982\u679c\u4e8c\u7ea7\u4e3b\u952e\u80fd\u591f\u8986\u76d6\u67e5\u8be2\uff0c\u5219\u53ef\u4ee5\u907f\u514d\u5bf9\u4e3b\u952e\u7d22\u5f15\u7684\u4e8c\u6b21\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n<p>\u8986\u76d6\u7d22\u5f15\u5fc5\u987b\u8981\u5b58\u50a8\u7d22\u5f15\u5217\u7684\u503c\uff0c\u800c\u54c8\u5e0c\u7d22\u5f15\u3001\u7a7a\u95f4\u7d22\u5f15\u548c\u5168\u6587\u7d22\u5f15\u90fd\u4e0d\u5b58\u50a8\u7d22\u5f15\u5217\u7684\u503c\u3002MySQL \u53ea\u80fd\u4f7f\u7528 B-Tree \u7d22\u5f15\u505a\u8986\u76d6\u7d22\u5f15\u3002<\/p>\n<p>\u5f53\u53d1\u8d77\u4e00\u4e2a\u88ab\u7d22\u5f15\u8986\u76d6\u7684\u67e5\u8be2\u65f6\uff0c\u5728 <code>explain<\/code> \u7684 <code>Extra<\/code> \u5217\u53ef\u4ee5\u770b\u5230 &#8220;Using Index&#8221; \u7684\u4fe1\u606f\u3002\uff08Extra \u5217\u7684 &#8220;Using Index&#8221; \u4e0e type \u7684 \u201cindex\u201d \u5b8c\u5168\u4e0d\u540c\uff0c type \u5217\u548c\u8986\u76d6\u7d22\u5f15\u6beb\u65e0\u5173\u7cfb\uff0c\u5b83\u53ea\u662f\u8868\u793a\u8fd9\u4e2a\u67e5\u8be2\u8bbf\u95ee\u6570\u636e\u7684\u65b9\u5f0f\uff0c\u6216\u8005\u8bf4\u662f MySQL \u67e5\u627e\u884c\u7684\u65b9\u5f0f\u3002\uff09<\/p>\n<p>MySQL \u80fd\u5728\u7d22\u5f15\u4e2d\u6700\u5de6\u524d\u7f00\u5339\u914d\u7684 LIKE \u6bd4\u8f83\uff0c\u56e0\u4e3a\u8be5\u64cd\u4f5c\u53ef\u4ee5\u8f6c\u6362\u4e3a\u7b80\u5355\u7684\u6bd4\u8f83\u64cd\u4f5c\uff0c\u4f46\u662f\u5982\u679c\u662f\u901a\u914d\u7b26\u5f00\u5934\u7684 LIKE \u67e5\u8be2\uff0c\u5b58\u50a8\u5f15\u64ce\u5c31\u65e0\u6cd5\u505a\u6bd4\u8f83\u5339\u914d\u3002<\/p>\n<h1>\u4f7f\u7528\u7d22\u5f15\u626b\u63cf\u6765\u505a\u6392\u5e8f<\/h1>\n<p>MySQL \u6709\u4e24\u79cd\u65b9\u5f0f\u53ef\u4ee5\u751f\u6210\u6709\u5e8f\u7684\u7ed3\u679c\uff1a\u901a\u8fc7\u6392\u5e8f\uff0c\u6216\u8005\u6309\u7d22\u5f15\u987a\u5e8f\u626b\u63cf\u3002\u5982\u679c <code>explain<\/code> \u51fa\u6765\u7684 type \u5217\u7684\u503c\u4e3a \u201cindex\u201d \u8bf4\u660e MySQL \u4f7f\u7528\u4e86\u7d22\u5f15\u626b\u63cf\u6765\u505a\u6392\u5e8f\u3002<\/p>\n<p>\u5982\u679c\u7d22\u5f15\u4e0d\u80fd\u8986\u76d6\u67e5\u8be2\u6240\u9700\u7684\u5168\u90e8\u5217\uff0c\u90a3\u5c31\u4e0d\u5f97\u4e0d \u6bcf\u626b\u63cf\u4e00\u6761\u7d22\u5f15\u8bb0\u5f55\u5c31\u90fd\u56de\u8868\u67e5\u8be2\u4e00\u6b21\u5bf9\u5e94\u7684\u884c\u3002\u8fd9\u57fa\u672c\u90fd\u662f\u968f\u673a I\/O\uff0c\u56e0\u6b64\u6309\u7d22\u5f15\u987a\u5e8f\u8bfb\u53d6\u6570\u636e\u7684\u901f\u5ea6\u901a\u5e38\u8981\u6bd4\u987a\u5e8f\u5168\u8868\u626b\u63cf\u6162\uff0c\u5c24\u5176\u662f\u5728 I\/O \u5bc6\u96c6\u578b\u7684\u5de5\u4f5c\u8d1f\u8f7d\u65f6\u3002<\/p>\n<p>\u53ea\u6709\u5f53\u7d22\u5f15\u7684\u5217\u987a\u5e8f\u548c <code>order by<\/code> \u5b50\u53e5\u7684\u987a\u5e8f\u5b8c\u5168\u4e00\u81f4\uff0c\u5e76\u4e14\u6240\u6709\u5217\u7684\u6392\u5e8f\u65b9\u5411\uff08\u964d\u5e8f\u6216\u5347\u5e8f\uff09<strong>\u90fd<\/strong>\u4e00\u6837\u65f6\uff0cMySQL\u624d\u80fd\u591f\u4f7f\u7528\u7d22\u5f15\u6765\u5bf9\u7ed3\u679c\u505a\u6392\u5e8f\u3002<br \/>\n\u5982\u679c\u67e5\u8be2\u9700\u8981\u5173\u8054\u591a\u5f20\u8868\uff0c\u5219\u53ea\u6709\u5f53 <code>order by<\/code> \u5b50\u53e5\u5f15\u7528\u7684\u5b57\u6bb5\u5168\u90e8\u4e3a\u7b2c\u4e00\u4e2a\u8868\u65f6\uff0c\u624d\u80fd\u4f7f\u7528\u7d22\u5f15\u505a\u6392\u5e8f\u3002<code>order by<\/code> \u5b50\u53e5\u548c\u67e5\u627e\u578b\u67e5\u8be2\u7684\u9650\u5236\u662f\u4e00\u6837\u7684\uff1a\u9700\u8981\u6ee1\u8db3\u7d22\u5f15\u7684\u6700\u5de6\u524d\u7f00\u7684\u8981\u6c42\uff0c\u5426\u5219 MySQL \u90fd\u9700\u8981\u6267\u884c\u6392\u5e8f\uff0c\u800c\u65e0\u6cd5\u5229\u7528\u7d22\u5f15\u6392\u5e8f\u3002<\/p>\n<p>\u6709\u4e00\u79cd\u60c5\u51b5\u4e0b order by \u5b50\u53e5\u53ef\u4ee5\u5728\u4e0d\u6ee1\u8db3\u7d22\u5f15\u7684\u6700\u5de6\u524d\u7f00\u7684\u8981\u6c42\uff0c\u5c31\u662f\u524d\u5bfc\u5217\u4e3a\u5e38\u91cf\u65f6\uff08\u7528\u524d\u5bfc\u5217\u7b49\u4e8e\u7ed9\u5b9a\u503c\u7684\u5f62\u5f0f\uff09\u3002<\/p>\n<h1>\u5197\u4f59\u548c\u91cd\u590d\u7d22\u5f15<\/h1>\n<p>MySQL \u5141\u8bb8\u5728\u76f8\u540c\u5217\u4e0a\u521b\u5efa\u591a\u4e2a\u7d22\u5f15\uff0c\u7d22\u5f15\u7c7b\u578b\u4e0d\u540c\uff0c\u5c31\u4e0d\u7b97\u91cd\u590d\u7d22\u5f15\u3002\uff08Oracle \u4e0d\u533a\u5206\u7d22\u5f15\u7c7b\u578b\uff0c\u53ea\u770b\u7d22\u5f15\u7684\u5217\u548c\u987a\u5e8f\uff09<\/p>\n<p>\u91cd\u590d\u7d22\u5f15\u662f\u6307\u5728\u76f8\u540c\u7684\u5217\u4e0a\u6309\u7167\u76f8\u540c\u7684\u987a\u5e8f\u521b\u5efa\u7684\u76f8\u540c\u7c7b\u578b\u7684\u7d22\u5f15\u3002<\/p>\n<p>MySQL \u7684\u552f\u4e00\u7ea6\u675f\u548c\u4e3b\u952e\u90fd\u662f\u901a\u8fc7\u7d22\u5f15\u5b9e\u73b0\u7684\u3002<\/p>\n<h1>\u7d22\u5f15\u548c\u9501<\/h1>\n<p>\u7d22\u5f15\u53ef\u4ee5\u8ba9\u67e5\u8be2\u9501\u5b9a\u66f4\u5c11\u7684\u884c\u3002<\/p>\n<p>InnoDB \u53ea\u6709\u5728\u8bbf\u95ee\u884c\u7684\u65f6\u5019\u624d\u4f1a\u5bf9\u5176\u52a0\u9501\uff0c\u800c\u7d22\u5f15\u80fd\u591f\u51cf\u5c11 InnoDB \u8bbf\u95ee\u7684\u884c\u6570\uff0c\u4ece\u800c\u51cf\u5c11\u9501\u7684\u6570\u91cf\u3002\u4f46\u8fd9\u53ea\u6709\u5f53 InnoDB \u5728\u5b58\u50a8\u5f15\u64ce\u5c42\u80fd\u591f\u8fc7\u6ee4\u6389\u6240\u6709\u4e0d\u9700\u8981\u7684\u884c\u65f6\u624d\u6709\u6548\uff08\u4e5f\u5c31\u662f\u4ece\u5b58\u50a8\u5f15\u64ce\u5c42\u8fd4\u56de\u5230\u670d\u52a1\u5668\u5c42\u8fc7\u6ee4\u7684\u4ecd\u7136\u4f1a\u9501\u4f4f\u884c\uff09\u3002<\/p>\n<p>InnoDB \u5728\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u4f7f\u7528\u5171\u4eab\uff08\u8bfb\uff09\u9501\uff0c\u4f46\u8bbf\u95ee\u4e3b\u952e\u7d22\u5f15\u9700\u8981\u6392\u4ed6\uff08\u5199\uff09\u9501\u3002\u8fd9\u6d88\u9664\u4e86\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\u7684\u53ef\u80fd\u6027\uff0c\u5e76\u4e14\u4f7f\u5f97 <code>select for update<\/code> \u6bd4 <code>lock in share mode<\/code> \u6216\u9501\u5b9a\u67e5\u8be2\u8981\u6162\u5f88\u591a\u3002<\/p>\n<h1>\u5176\u4ed6<\/h1>\n<p>\u5c3d\u53ef\u80fd\u5c06\u9700\u8981\u505a\u8303\u56f4\u67e5\u8be2\u7684\u5217\u653e\u5230\u7d22\u5f15\u7684\u540e\u9762\uff0c\u4ee5\u4fbf\u4f18\u5316\u5668\u80fd\u4f7f\u7528\u5c3d\u53ef\u80fd\u591a\u7684\u7d22\u5f15\u5217\u3002<\/p>\n<p>\u5bf9\u4e8e\u8303\u56f4\u6761\u4ef6\u67e5\u8be2\uff0cMySQL \u65e0\u6cd5\u518d\u4f7f\u7528\u8303\u56f4\u5217\u540e\u9762\u7684\u5176\u4ed6\u7d22\u5f15\u5217\uff0c\u5bf9\u4e8e\u201c\u591a\u4e2a\u7b49\u503c\u6761\u4ef6\u67e5\u8be2\uff08<code>in<\/code> \u5b50\u53e5\uff09\u201d\u5219\u6ca1\u6709\u8fd9\u4e2a\u9650\u5236\u3002<\/p>\n<p>\u5ef6\u8fdf\u5173\u8054\uff1a\u901a\u8fc7\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\u67e5\u8be2\u8fd4\u56de\u9700\u8981\u7684\u4e3b\u952e\uff0c\u518d\u6839\u636e\u8fd9\u4e9b\u4e3b\u952e\u5173\u8054\u539f\u8868\u83b7\u5f97\u9700\u8981\u7684\u884c\u3002<\/p>\n<p>\u5728\u9009\u62e9\u548c\u7f16\u5199\u5229\u7528\u7d22\u5f15\u7684\u67e5\u8be2\u65f6\uff0c\u8bb0\u4f4f\u4e0b\u9762\u4e09\u4e2a\u539f\u5219\uff1a<\/p>\n<ul>\n<li>\u5355\u884c\u8bbf\u95ee\u662f\u5f88\u6162\u7684\u3002\uff08\u7279\u522b\u662f\u673a\u68b0\u786c\u76d8\u5b58\u50a8\uff0cSSD \u7684\u968f\u673a I\/O \u5feb\u5f88\u591a\uff0c\u4e0d\u8fc7\u8fd9\u70b9\u4ecd\u7136\u6210\u7acb\u3002\uff09\u6700\u597d\u8bfb\u53d6\u7684\u5757\u4e2d\u5305\u542b\u5c3d\u53ef\u80fd\u591a\u6240\u9700\u7684\u884c\u3002\u4f7f\u7528\u7d22\u5f15\u53ef\u4ee5\u521b\u5efa\u4f4d\u7f6e\u5f15\u7528\u4ee5\u63d0\u5347\u6548\u7387\u3002<\/li>\n<li>\u6309\u987a\u5e8f\u8bbf\u95ee\u8303\u56f4\u6570\u636e\u662f\u5f88\u5feb\u7684\u3002\u539f\u56e0\uff1a1\uff0c\u987a\u5e8f I\/O \u4e0d\u9700\u8981\u591a\u6b21\u78c1\u76d8\u5bfb\u9053\uff0c\u6240\u4ee5\u6bd4\u968f\u673a I\/O \u5feb\u5f88\u591a\uff08\u7279\u522b\u662f\u673a\u68b0\u786c\u76d8\uff09\uff1b2\uff0c\u5982\u679c\u670d\u52a1\u5668\u80fd\u591f\u6309\u9700\u8981\u987a\u5e8f\u8bfb\u53d6\u6570\u636e\uff0c\u90a3\u4e48\u5c31\u4e0d\u518d\u9700\u8981\u989d\u5916\u7684\u6392\u5e8f\u64cd\u4f5c\uff0c\u5e76\u4e14 <code>group by<\/code> \u67e5\u8be2\u4e5f\u65e0\u987b\u518d\u505a\u6392\u5e8f\u548c\u5c06\u884c\u6309\u7ec4\u8fdb\u884c\u805a\u5408\u8ba1\u7b97\u3002<\/li>\n<li>\u7d22\u5f15\u8986\u76d6\u67e5\u8be2\u662f\u5f88\u5feb\u7684\u3002\u5b58\u50a8\u5f15\u64ce\u4e0d\u9700\u8981\u56de\u8868\u67e5\u627e\u884c\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u91cd\u65b0\u770b\u4e86\u4e00\u904d\u505a\u5f97\u8bb0\u5f55\u3002 \u72ec\u7acb\u7684\u5217 \u7d22\u5f15\u5217\u4e0d\u80fd\u662f\u8868\u8fbe\u5f0f\u7684\u4e00\u90e8\u5206\uff0c\u4e5f\u4e0d\u80fd\u662f\u51fd\u6570\u7684\u53c2\u6570 &hellip; <a href=\"https:\/\/coderbee.net\/index.php\/db\/20170818\/1539\">\u7ee7\u7eed\u9605\u8bfb <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[215,279,278],"_links":{"self":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1539"}],"collection":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/comments?post=1539"}],"version-history":[{"count":3,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1539\/revisions"}],"predecessor-version":[{"id":2143,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1539\/revisions\/2143"}],"wp:attachment":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/media?parent=1539"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/categories?post=1539"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/tags?post=1539"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}