{"id":10006559,"date":"2022-09-21T13:10:47","date_gmt":"2022-09-21T05:10:47","guid":{"rendered":"https:\/\/ityet.com\/?p=10006559"},"modified":"2022-09-21T13:10:47","modified_gmt":"2022-09-21T05:10:47","slug":"%e4%b8%80%e6%9d%a1sql%e4%ba%86%e8%a7%a3mysql%e7%9a%84%e6%9e%b6%e6%9e%84%e8%ae%be%e8%ae%a1","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10006559","title":{"rendered":"\u4e00\u6761sql\u4e86\u89e3MYSQL\u7684\u67b6\u6784\u8bbe\u8ba1"},"content":{"rendered":"<p><strong>1 \u524d\u8a00<\/strong><br \/>\u5bf9\u4e8e\u4e00\u4e2a\u670d\u52a1\u7aef\u5f00\u53d1\u6765\u8bf4 MYSQL \u53ef\u80fd\u662f\u4ed6\u4f7f\u7528\u6700\u719f\u6089\u7684\u6570\u636e\u5e93\u5de5\u5177\uff0c\u7136\u800c\uff0c\u5927\u90e8\u5206\u7684Java\u5de5\u7a0b\u5e08\u5bf9MySQL\u7684\u4e86\u89e3\u548c\u638c\u63e1\u7a0b\u5ea6\uff0c\u5927\u81f4\u5c31\u505c\u7559\u5728\u8fd9\u4e48\u4e00\u4e2a\u9636\u6bb5:\u5b83\u53ef\u4ee5\u5efa\u5e93\u3001\u5efa\u8868\u3001\u5efa\u7d22\u5f15\uff0c\u7136\u540e\u5c31\u662f\u5bf9\u91cc\u9762\u7684\u6570\u636e\u8fdb\u884c\u589e\u5220\u6539\u67e5\uff0c\u8bed\u53e5\u6027\u80fd\u6709\u70b9\u5dee\uff1f\u6ca1\u5173\u7cfb\uff0c\u5728\u8868\u91cc\u5efa\u51e0\u4e2a\u7d22\u5f15\u6216\u8005\u8c03\u6574\u4e00\u4e0b\u67e5\u8be2\u903b\u8f91\u5c31\u53ef\u4ee5\u4e86\uff0c\u4e00\u6761sql\uff0cMYSQL\u662f\u5982\u4f55\u5904\u7406\u7684\uff0c\u4e3a\u6211\u4eec\u505a\u4e86\u4ec0\u4e48\uff0c\u5b8c\u5168\u662f\u4e2a\u9ed1\u76d2\u3002\u672c\u6587\u4e3b\u8981\u901a\u8fc7sql\u6267\u884c\u7684\u8fc7\u7a0b\u6253\u7834\u8fd9\u6837\u4e00\u4e2a\u9ed1\u76d2\u7684\u8ba4\u77e5\uff0c\u6765\u4e86\u89e3MYSQL\u7684\u903b\u8f91\u67b6\u6784\u3002<\/p>\n<p>MYSQL\u7684\u903b\u8f91\u67b6\u6784\u53ef\u5206\u4e3a3\u5c42:\u5e94\u7528\u5c42\u3001\u670d\u52a1\u5c42\u3001\u5b58\u50a8\u5f15\u64ce\u5c42\u3002\u5176\u4e2d\u5b58\u50a8\u5f15\u64ce\u662fMYSQL\u6700\u6709\u7279\u8272\u7684\u5730\u65b9\uff0cMySQL\u533a\u522b\u4e8e\u5176\u4ed6\u6570\u636e\u5e93\u7684\u6700\u91cd\u8981\u7279\u70b9\u662f\u5176\u63d2\u4ef6\u5f0f\u7684\u8868\u5b58\u50a8\u5f15\u64ce\uff0c\u672c\u6587\u4e5f\u5c06\u7740\u91cd\u804a\u804a\u6700\u5e38\u7528\u7684innoDB\u5b58\u50a8\u5f15\u64ce\u7684\u67b6\u6784\u8bbe\u8ba1\u539f\u7406\uff0c\u5047\u8bbe\u73b0\u6709\u5982\u4e0bsql\uff1a<\/p>\n<p>update users set name=\u2019zhangsan\u2019 where id = 10<\/p>\n<p>\u4f5c\u4e3a\u4e00\u4e2ajava\u670d\u52a1\u7aef\u5de5\u7a0b\u5e08\uff0c\u89c1\u5230\u8fd9\u6837\u4e00\u4e2asql\uff0c\u672c\u80fd\u7684\u8111\u6d77\u4e2d\u7acb\u523b\u5c31\u6d6e\u73b0\u51fa\u5982\u4e0b\u4fe1\u606f\uff1a<\/p>\n<p>\u4e00\u4e2a\u8868\u540d\u4e3ausers\u7684\u8868<br \/>\u6709\u4e24\u4e2a\u5b57\u6bb5 id\u3001name\uff0cid\u662f\u4e3b\u952e<br \/>\u628ausers\u8868\u91cc\u7684id=10\u7684\u8fd9\u4e2a\u7528\u6237\u540d\u4fee\u6539\u4e3a\u201czhangsan\u201d<br \/>\u90a3\u4e48MYSQL\u662f\u5982\u4f55\u5904\u7406\u8fd9\u6837\u4e00\u4e2asql\u5462\uff1f\u5e26\u7740\u8fd9\u4e2a\u95ee\u9898\uff0c\u6211\u4eec\u6765\u770b\u4e00\u4e0bMYSQL\u662f\u5982\u4f55\u901a\u8fc7\u4e00\u4e2a\u4e2a\u7ec4\u4ef6\u6765\u5904\u7406\u8fd9\u4e2asql\uff0c\u6765\u4e86\u89e3MYSQL\u7684\u6574\u4f53\u67b6\u6784<\/p>\n<p><strong>2 \u5e94\u7528\u5c42<\/strong><\/p>\n<p><strong>2.1 \u8fde\u63a5\u7ebf\u7a0b\u5904\u7406<\/strong><\/p>\n<p>\u5f53MYSQL\u9762\u5bf9\u4e0a\u9762\u7684sql\uff0c\u9996\u5148\u5e94\u8be5\u505a\u4ec0\u4e48\u5462\uff1f\u662f\u5982\u4f55\u89e3\u6790\uff1f\u5982\u4f55\u9009\u62e9\u7d22\u5f15\uff1f\u5982\u4f55\u63d0\u4ea4\u4e8b\u52a1\uff1f\u5f53\u7136\u4e0d\u662f\uff0c\u9996\u5148\u5e94\u8be5\u89e3\u51b3\u7684\u662f\u600e\u4e48\u628asql\u8bed\u53e5\u4f20\u7ed9\u5b83\u3002\u5927\u5bb6\u90fd\u77e5\u9053\uff0c\u5982\u679c\u6211\u4eec\u8981\u8bbf\u95ee\u6570\u636e\u5e93\uff0c\u90a3\u4e48\uff0c\u9996\u5148\u5c31\u9700\u8981\u548c\u6570\u636e\u5e93\u5efa\u7acb\u8fde\u63a5\uff0c\u90a3\u4e48\u8fd9\u4e2a\u8fde\u63a5\u7531\u8c01\u6765\u5efa\u5462\uff0c\u7b54\u6848\u5c31\u662fMYSQL\u9a71\u52a8\uff0c\u4e0b\u9762\u8fd9\u6bb5maven\u914d\u7f6e\u5927\u5bb6\u5e94\u8be5\u90fd\u5f88\u719f\u6089<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zlV\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>java\u7a0b\u5e8f\u5c31\u662f\u901a\u8fc7\u8fd9\u4e2a\u9a71\u52a8\u5305\u6765\u4e0e\u6570\u636e\u5e93\u5efa\u7acb\u7f51\u7edc\u8fde\u63a5\u3002<br \/>\u4e0b\u56fe\u793a\u610f\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zlW\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u5230\u8fd9\u6837\u4e00\u4e2a\u573a\u666f\uff1ajava\u7a0b\u5e8f\u5f88\u591a\u4e2a\u7ebf\u7a0b\u5e76\u53d1\u8bf7\u6c42\u6267\u884c\u4e0a\u8ff0sql\uff0c\u6211\u4eec\u90fd\u77e5\u9053\u6570\u636e\u5e93\u8fde\u63a5\u662f\u975e\u5e38\u5360\u7528\u8d44\u6e90\u7684\uff0c\u5c24\u5176\u662f\u5728\u9ad8\u5e76\u53d1\u7684\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u6bcf\u6b21\u90fd\u53bb\u5efa\u7acb\u6570\u636e\u5e93\u8fde\u63a5\u5c31\u4f1a\u6709\u6027\u80fd\u95ee\u9898\uff0c\u4e5f\u4f1a\u5f71\u54cd\u4e00\u4e2a\u5e94\u7528\u7a0b\u5e8f\u7684\u5ef6\u5c55\u6027\uff0c\u9488\u5bf9\u8fd9\u4e2a\u95ee\u9898\uff0c\u8fde\u63a5\u6c60\u51fa\u73b0\u4e86\u3002<br \/>\u4e0b\u56fe\u793a\u610f\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zlX\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4ece\u56fe\u4e2d\u53ef\u89c1\u7f51\u7edc\u8fde\u63a5\u4ea4\u7531\u7ebf\u7a0b3\u76d1\u542c\u548c\u8bfb\u53d6sql\u8bf7\u6c42\uff0c\u81f3\u6b64MYSQL\u5df2\u7ecf\u6536\u5230\u6211\u4eec\u7684\u8bf7\u6c42\uff0c\u5f53\u7136MYSQL\u5728\u5efa\u7acb\u8fde\u63a5\u65f6\u8fd8\u505a\u4e86\u7528\u6237\u9274\u6743,\u9274\u6743\u4f9d\u636e\u662f: \u7528\u6237\u540d\uff0c\u5ba2\u6237\u7aef\u4e3b\u673a\u5730\u5740\u548c\u7528\u6237\u5bc6\u7801;\u5728\u83b7\u53d6\u8fde\u63a5\u540e\uff0c\u5904\u7406\u8bf7\u6c42\u65f6\u8fd8\u4f1a\u505asql\u8bf7\u6c42\u7684\u5b89\u5168\u6821\u9a8c\uff0c\u6839\u636e\u7528\u6237\u7684\u6743\u9650\u5224\u65ad\u7528\u6237\u662f\u5426\u53ef\u4ee5\u6267\u884c\u8fd9\u6761sql\u3002<\/p>\n<p><strong>3 \u670d\u52a1\u5c42<\/strong><\/p>\n<p><strong>3.1 SQL \u63a5\u53e3<\/strong><\/p>\n<p>\u4ece\u4e0a\u56fe\u4e2d\u6211\u4eec\u77e5\u9053\u7ebf\u7a0b3\u8d1f\u8d23\u76d1\u542c\u5e76\u8bfb\u53d6sql\uff0c\u62ff\u5230\u8fd9\u4e2asql\u4e4b\u540e\uff0c\u5982\u4f55\u6267\u884c\u662f\u4e00\u9879\u6781\u5176\u590d\u6742\u7684\u4efb\u52a1\uff0c\u6240\u4ee5MYSQL\u63d0\u4f9b\u4e86SQL\u63a5\u53e3\u8fd9\u4e48\u4e00\u4e2a\u7ec4\u4ef6\uff0c\u7ebf\u7a0b3\u4f1a\u5c06sql\u8f6c\u4ea4\u7ed9SQL\u63a5\u53e3\u6765\u6267\u884c\u5982\u4e0b\u56fe\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zlY\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>SQL\u63a5\u53e3\u5177\u4f53\u5904\u7406\u529f\u80fd\u6709\uff1aDDL\u3001DML\u3001\u5b58\u50a8\u8fc7\u7a0b\u3001\u89c6\u56fe\u3001\u89e6\u53d1\u5668\u7b49\u3002<\/p>\n<p><strong>3.2 SQL\u89e3\u6790\u5668<\/strong><\/p>\n<p>\u63a5\u7740\u95ee\u9898\u6765\u4e86\uff0cSQL\u63a5\u53e3\u5982\u4f55\u6267\u884c\u672c\u6587sql\u5462\uff1f\uff0c\u6570\u636e\u5e93\u600e\u4e48\u7406\u89e3\u672c\u6587\u8fd9\u4e2asql\u5462\uff1f\u76f8\u4fe1\u61c2sql\u8bed\u6cd5\u7684\u4eba\u7acb\u9a6c\u5c31\u80fd\u77e5\u9053\u4ec0\u4e48\u610f\u601d\uff0c\u4f46\u662fMYSQL\u662f\u4e2a\u7cfb\u7edf\u4e0d\u662f\u4eba\uff0c\u5b83\u65e0\u6cd5\u76f4\u63a5\u7406\u89e3sql\u7684\u610f\u601d\uff0c\u8fd9\u4e2a\u65f6\u5019\u5173\u952e\u7684\u7ec4\u4ef6\u51fa\u573a\u4e86\uff0cSQL\u89e3\u6790\u5668\u7684\u4f5c\u7528\u4e3b\u8981\u5c31\u662f\u662f\u89e3\u6790sql\u8bed\u53e5\uff0c\u6700\u7ec8\u751f\u6210\u8bed\u6cd5\u6811\uff0c\u6bd4\u5982\u672c\u6587sql\u5c31\u53ef\u4ee5\u62c6\u89e3\u6210\u5982\u4e0b\u51e0\u4e2a\u90e8\u5206\uff1a<\/p>\n<ol>\n<li>\u9700\u8981\u4eceusers\u8868\u91cc\u66f4\u65b0\u6570\u636e<\/li>\n<li>\u9700\u8981\u66f4\u65b0id\u5b57\u6bb5\u662f10\u7684\u90a3\u884c\u6570\u636e<\/li>\n<li>\u9700\u8981\u628a\u8fd9\u884c\u6570\u636e\u7684name\u5b57\u6bb5\u7684\u503c\u6539\u4e3a \u201czhangsan\u201d<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zlZ\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/li>\n<\/ol>\n<p><strong>3.3 SQL\u4f18\u5316\u5668<\/strong><\/p>\n<p>\u5f53\u901a\u8fc7SQL \u89e3\u6790\u5668\u7406\u89e3\u4e86sql\u8bed\u53e5\u8981\u5e72\u4ec0\u4e48\u4e4b\u540e\uff0c\u8be5\u5982\u4f55\u5b9e\u73b0\u5462\uff0c\u4ee5\u672c\u6587\u7684\u66f4\u65b0\u8bed\u53e5\u4e3a\u4f8b\uff0c\u6211\u4eec\u53ef\u4ee5\u6709\u4ee5\u4e0b\u4e24\u79cd\u5b9e\u73b0\u65b9\u5f0f\uff1a<\/p>\n<p>\u76f4\u63a5\u5b9a\u4f4d\u5230users\u8868\u4e2did\u5b57\u6bb5\u7b49\u4e8e10\u7684\u4e00\u884c\u6570\u636e\uff0c\u7136\u540e\u67e5\u51fa\u8fd9\u884c\u6570\u636e\u6570\u636e\uff0c\u7136\u540e\u8bbe\u7f6ename\u5b57\u6bb5\u4e3a\u201czhangsan\u201d\uff1b<br \/>\u4e5f\u53ef\u4ee5\u901a\u8fc7\u66f4\u65b0name\u5b57\u6bb5\u7d22\u5f15\u7684\u65b9\u5f0f\u5728name\u7d22\u5f15\u4e0a\u904d\u5386id\u7b49\u4e8e10\u7684\u7d22\u5f15\u503c\uff0c\u7136\u540e\u8bbe\u7f6ename\u5b57\u6bb5\u4e3a\u201czhangsan\u201d\u3002<br \/>\u4e0a\u9762\u4e24\u79cd\u9014\u5f84\u90fd\u80fd\u5b9e\u73b0\u6700\u7ec8\u7ed3\u679c\uff0c\u663e\u7136\u7b2c\u4e00\u79cd\u8def\u5f84\u66f4\u597d\u4e00\u4e9b\uff0c\u6240\u4ee5,SQL\u4f18\u5316\u5668\u5c31\u662f\u4ece\u4f17\u591a\u5b9e\u73b0\u8def\u5f84\u4e2d\u9009\u5219\u4e00\u6761\u6700\u4f18\u7684\u8def\u5f84\u51fa\u6765\uff0c\u4e5f\u5c31\u662f\u6211\u4eec\u5e38\u8bf4\u7684\u6267\u884c\u8ba1\u5212\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zl9\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p><strong>3.4 \u6267\u884c\u5668<\/strong><\/p>\n<p>\u901a\u8fc7SQL\u4f18\u5316\u5668\u6211\u4eec\u5f97\u5230\u4e00\u5957\u6267\u884c\u8ba1\u5212\uff0c\u90a3\u4e48\uff0c\u8fd9\u4e2a\u8ba1\u5212\u600e\u4e48\u6267\u884c\u5462\uff1f\u8fd9\u4e2a\u65f6\u5019\u5c31\u4e0d\u5f97\u4e0d\u63d0MYSQL\u5b58\u50a8\u5f15\u64ce\uff0c\u6211\u4eec\u90fd\u77e5\u9053MySQL\u548c\u5176\u4ed6\u5173\u7cfb\u578b\u6570\u636e\u5e93\u4e0d\u4e00\u6837\u7684\u5730\u65b9\u5728\u4e8e\u5b83\u7684\u5f39\u6027\u4ee5\u53ca\u53ef\u4ee5\u901a\u8fc7\u63d2\u4ef6\u5f62\u5f0f\u63d0\u4f9b\u4e0d\u540c\u79cd\u7c7b\u7684\u5b58\u50a8\u5f15\u64ce\uff0c\u7c7b\u4f3cjava\u63a5\u53e3\u7684\u591a\u5b9e\u73b0\uff0cMYSQL\u80af\u5b9a\u4f1a\u6709\u4e00\u5957\u6807\u51c6\u7684\u5b58\u50a8\u5f15\u64ce\u63a5\u53e3\uff0c\u800c\u6267\u884c\u5668\u5c31\u662f\u6309\u7167\u6267\u884c\u8ba1\u5212\u4e00\u6b65\u4e00\u6b65\u7684\u8c03\u7528\u5b58\u50a8\u5f15\u64ce\u63a5\u53e3\u5b8c\u6210sql\u6267\u884c\u800c\u5df2\uff0c\u5982\u4e0b\u56fe\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zme\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4e0a\u56fe\u4e13\u95e8\u5c06binlog\u6807\u51fa\u6765\u662f\u4e3a\u4e86\u548c\u4e0b\u6587innodb\u5b58\u50a8\u5f15\u64ce\u7684undo log\u3001redo log\u505a\u533a\u5206\uff0c\u5f3a\u8c03binlog\u662fserver\u5c42\u7684\u65e5\u5fd7\uff0c\u540e\u7eedbinlog \u548credo log\u7684\u4e24\u9636\u6bb5\u65b9\u5f0f\u5b8c\u6210\u4e8b\u52a1\u7684\u63d0\u4ea4\u4f1a\u518d\u6b21\u63d0\u5230\u3002<\/p>\n<p><strong>3.5 \u67e5\u8be2\u7f13\u5b58<\/strong><\/p>\n<p>MYSQL\u670d\u52a1\u5c42\u4e3a\u8ffd\u6c42\u9ad8\u6548\u4e5f\u5f15\u5165\u4e86QUERY BUFFER \u8fd9\u4e2a\u7ec4\u4ef6\uff0c\u4f46\u662f\u8fd9\u4e2a\u7ec4\u4ef6\u6bd4\u8f83\u9e21\u808b\uff0c\u7f13\u5b58\u4e0d\u4ec5\u9700\u8981sql\u5168\u5b57\u5339\u914d\u547d\u4e2d\uff0c\u800c\u4e14\u5bf9\u57fa\u7840\u8868\u7684\u4efb\u4f55\u4fee\u6539\u90fd\u4f1a\u5bfc\u81f4\u8fd9\u4e9b\u8868\u7684\u6240\u6709\u7f13\u5b58\u5931\u6548\uff0c\u65e2\u4e0d\u7b26\u5408\u73b0\u5728\u7528\u6237\u53d8\u91cf\u7684\u5f00\u53d1\u6a21\u5f0f\uff0c\u5927\u90e8\u5206\u65f6\u5019\u4e5f\u4e0d\u9ad8\u6548\u3002MYSQL\u4ece5.7\u5f00\u59cb\u4e0d\u63a8\u8350\u4f7f\u7528\u9ed8\u8ba4\u5173\u95ed\uff0c8.0\u4e2d\u4e0d\u518d\u652f\u6301\uff0c\u8be6\u7ec6\u539f\u56e0\u5982\u4e0b\u56fe\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmh\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u622a\u56fe\u6765\u6e90MYSQL\u5f00\u53d1\u8005\u4e13\u533a\u6587\u6863\uff1aMySQL :: MySQL 8.0: Retiring Support for the Query Cache<\/p>\n<p><strong>4 \u5b58\u50a8\u5f15\u64ce\u5c42<\/strong><\/p>\n<p><strong>4.1 \u6982\u8ff0<\/strong><\/p>\n<p>\u4e0a\u6587\u6267\u884c\u5668\u62ff\u5230\u6267\u884c\u8ba1\u5212\u540e\uff0c\u8c03\u7528\u5b58\u50a8\u5f15\u64ce\u7684\u63a5\u53e3\u6765\u5b8c\u6210sql\u7684\u6267\u884c\uff0c\u90a3\u4e48\u5b58\u50a8\u5f15\u64ce\u5982\u4f55\u5e2e\u52a9\u6211\u4eec\u53bb\u8bbf\u95ee\u3001\u64cd\u4f5c\u5185\u5b58\u4ee5\u53ca\u78c1\u76d8\u4e0a\u7684\u6570\u636e\u5462\uff1f\u6211\u4eec\u90fd\u77e5\u9053MYSQL\u7684\u5b58\u50a8\u5f15\u64ce\u6709\u5f88\u591a\uff0c\u5b9e\u73b0\u65b9\u5f0f\u5404\u4e00\uff0c\u4e0b\u9762\u8ba9\u6211\u4eec\u7ee7\u7eed\u901a\u8fc7\u4e0a\u6587\u7684sql\u6765\u521d\u6b65\u4e86\u89e3\u6211\u4eec\u5e38\u7528\u7684Innodb\u5b58\u50a8\u5f15\u64ce\u7684\u6838\u5fc3\u539f\u7406\u548c\u67b6\u6784\u8bbe\u8ba1<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmm\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u91cd\u6e29\u4e00\u4e0b\u672c\u6587sql\uff1a<\/p>\n<p>update users set name=\u2019zhangsan\u2019 where id = 10 \u2014-\u5386\u53f2name = \u2018lisi\u2019<\/p>\n<p>4.2 \u7f13\u51b2\u6c60\uff08buffer pool\uff09<\/p>\n<p>InnoDB\u5b58\u50a8\u5f15\u64ce\u4e2d\u6709\u4e00\u4e2a\u975e\u5e38\u91cd\u8981\u7684\u653e\u5728\u5185\u5b58\u91cc\u7684\u7ec4\u4ef6\uff0c\u5c31\u662f\u7f13\u51b2\u6c60\uff08Buffer Pool\uff09\uff0c\u8fd9\u91cc\u9762\u4f1a\u7f13\u5b58\u5f88\u591a\u7684\u6570\u636e\uff0c\u4ee5\u4fbf\u4e8e\u4ee5\u540e\u5728\u67e5\u8be2\u7684\u65f6\u5019\uff0c\u4e07\u4e00\u4f60\u8981\u662f\u5185\u5b58\u7f13\u51b2\u6c60\u91cc\u6709\u6570\u636e\uff0c\u5c31\u53ef\u4ee5\u4e0d\u7528\u53bb\u67e5\u78c1\u76d8\u4e86\uff0c\u5982\u4e0b\u56fe\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmn\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u7f13\u51b2\u6c60\uff08buffer pool\uff09\u5728Innodb\u4e2d\u7684\u5730\u4f4d\u7c7b\u4f3c\u4e8e\u6211\u4eec\u73b0\u5728\u7cfb\u7edf\u8bbe\u8ba1\u4e2dredis\u7684\u5730\u4f4d\uff0c\u5728Innodb\u4e2d\u5f15\u5165\u8fd9\u4e00\u7ec4\u4ef6\u7684\u5c31\u662f\u4e3a\u4e86\u9ad8\u6548\u7684\u5b58\u53d6\uff0c\u6211\u4eec\u90fd\u77e5\u9053MYSQL\u67e5\u8be2\u6570\u636e\u5f88\u5feb\uff0c\u7a76\u5176\u539f\u56e0\u4e0d\u6b62\u662f\u7d22\u5f15\u67e5\u8be2\uff0c\u6df1\u5c42\u6b21\u7684\u539f\u56e0\u5c31\u662f\u6240\u6709\u7684\u589e\u5220\u6539\u67e5\u90fd\u662f\u5728buffer pool\u8fd9\u5757\u5185\u5b58\u4e0a\u64cd\u4f5c\u7684\uff0c\u76f8\u6bd4\u4e8e\u64cd\u4f5c\u78c1\u76d8\uff0c\u6548\u7387\u4e0d\u8a00\u81ea\u660e\u3002<\/p>\n<p><strong>4.2.1 \u6570\u636e\u9875\u3001\u7f13\u5b58\u9875\u548c\u810f\u9875<\/strong><\/p>\n<p>\u8fd8\u662f\u62ff\u6211\u4eec\u7684sql\u4e3e\u4f8b\uff0c\u66f4\u65b0id=10\u7684\u8fd9\u6761\u8bb0\u5f55\uff0c\u96be\u9053\u4ece\u78c1\u76d8\u91cc\u53ea\u62c9\u53d6id=10\u6570\u636e\u8fdb\u5165\u5185\u5b58\u4e2d\u5417\uff1f\u5f88\u660e\u663e\u4e0d\u662f\uff0c\u6bd5\u7adf\u52a0\u5165\u5185\u5b58\u7684\u8bb0\u5f55\u4e0d\u6b62\u8fd9\u4e00\u5f20\u8868\uff0c\u800c\u4e14\u5355\u8868\u6bcf\u884c\u8bb0\u5f55\u4e5f\u4e0d\u4e00\u6837\uff0c\u5185\u5b58\u7ba1\u7406\u4f1a\u975e\u5e38\u56f0\u96be\u7684\uff0c\u6240\u4ee5\uff0cMYSQL\u5bf9\u6570\u636e\u62bd\u8c61\u51fa\u6765\u7684\u4e00\u4e2a\u53eb\u6570\u636e\u9875\u7684\u903b\u8f91\u6982\u5ff5\uff0c\u6bcf\u9875\u56fa\u5b9a\u5927\u5c0f\u9ed8\u8ba416KB\uff0c\u53ef\u4ee5\u5b58\u591a\u6761\u6570\u636e\uff0c\u5e76\u4e14buffer pool\u91cc\u7684\u5b58\u50a8\u7ed3\u6784\u548c\u6570\u636e\u9875\u4e00\u81f4\uff0c\u8fd9\u6837\u5185\u5b58\u7ba1\u7406\u5c31\u4f1a\u7b80\u5355\u7684\u591a\uff0c\u6570\u636e\u9875\u6ce8\u518c\u5143\u6570\u636e\u540e\u52a0\u8f7d\u8fdb\u5185\u5b58\u540e\u5c31\u662f\u7f13\u5b58\u9875\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmo\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u5230\u5728\u7f13\u5b58\u9875\u5728sql\u66f4\u65b0\u5b8c\u8fd8\u672a\u5237\u56de\u786c\u76d8\u65f6\u6570\u636e\u548c\u78c1\u76d8\u4e2d\u7684\u6570\u636e\u9875\u662f\u4e0d\u4e00\u81f4\u7684\uff0c\u8fd9\u4e2a\u65f6\u5019\u6211\u4eec\u79f0\u8fd9\u79cd\u7f13\u5b58\u9875\u4e3a\u810f\u9875\u3002\u81f3\u4e8e\u540e\u7eed\u810f\u9875\u5982\u4f55\u843d\u76d8\u6682\u65f6\u4e0d\u63d0\u3002<\/p>\n<p><strong>4.2.2 \u5143\u6570\u636e<\/strong><\/p>\n<p>\u4ece\u4e0a\u56fe\u6211\u4eec\u770b\u5230buffer pool\u4e2d\u9664\u4e86\u7f13\u5b58\u9875\uff0c\u8fd8\u591a\u4e86\u4e00\u4e2a\u5143\u6570\u636e\u5185\u5b58\u7ed3\u6784\uff0c\u8fd9\u4e2a\u53ef\u4ee5\u7b80\u5355\u7684\u7406\u89e3\u4e3a\u767b\u8bb0\uff0c\u6bd4\u5982\u56e0\u4e3a\u75ab\u60c5\u5916\u5730\u4eba\u56de\u5bb6\u8fc7\u5e74\u4f1a\u88ab\u5f53\u5730\u653f\u5e9c\u8fdb\u884c\u767b\u8bb0\uff0c\u8bb0\u5f55\u4ece\u54ea\u6765\u3001\u5230\u54ea\u53bb\u7b49\u4fe1\u606f\uff0c\u4fbf\u4e8e\u7ba1\u7406\uff0cbuffer pool\u4e5f\u662f\u8fd9\u6837\u505a\u7684\uff1b\u4f46\u662f\u5143\u6570\u636e\u53ef\u4e0d\u6b62\u8bb0\u5f55\u7f13\u5b58\u9875\u7684\u78c1\u76d8\u5730\u5740\u548c\u5185\u5b58\u5730\u5740\u8fd9\u4e48\u7b80\u5355\uff0cbuffer pool\u6838\u5fc3\u539f\u7406\u90fd\u662f\u901a\u8fc7\u5143\u6570\u636e\u6765\u5b9e\u73b0\u7684<\/p>\n<p><strong>4.2.3 free\u94fe\u8868<\/strong><\/p>\n<p>buffer pool\u5728MYSQL\u521d\u59cb\u5316\u7684\u65f6\u5019\uff0c\u5c31\u6839\u636e\u914d\u7f6e\u5728\u5185\u5b58\u4e2d\u7533\u8bf7\u4e86\u4e00\u5757\u8fde\u7eed\u7684\u7a7a\u95f4\uff0c\u7533\u8bf7\u8fc7\u540e\u5c31\u6309\u6570\u636e\u9875\u7684\u5927\u5c0f\u548c\u5143\u6570\u636e\u7684\u5927\u5c0f\u8fdb\u884c\u5408\u7406\u7684\u5212\u5206\u51fa\u5f88\u591a\u4e2a\u8fde\u7eed\u7684\u3001\u7a7a\u7684\u7f13\u5b58\u9875,\u5f53\u9700\u8981\u67e5\u8be2\u6570\u636e\u7684\u65f6\u5019\u5c31\u4f1a\u4ece\u78c1\u76d8\u8bfb\u5165\u6570\u636e\u9875\u653e\u5165\u5230\u7f13\u5b58\u9875\u5f53\u4e2d,\u4f46\u662f\u7531\u4e8e\u810f\u9875\u7684\u5b58\u5728\uff0c\u6570\u636e\u8fd8\u672a\u5237\u76d8\u4e0d\u80fd\u4f7f\u7528\uff0c\u90a3\u4e48\u6570\u636e\u9875\u52a0\u8f7d\u8fdb\u54ea\u4e2a\u7f13\u5b58\u9875\u5c31\u662f\u4e2a\u95ee\u9898\u3002\u4e3a\u4e86\u89e3\u51b3\u54ea\u4e9b\u7f13\u5b58\u9875\u662f\u7a7a\u95f2\u7684\uff0cMYSQL\u56e2\u961f\u4e3aBuffer pool\u8bbe\u8ba1\u4e86\u4e00\u4e2afree\u94fe\u8868\uff0c\u5b83\u662f\u4e00\u4e2a\u53cc\u5411\u94fe\u8868\u7684\u6570\u636e\u7ed3\u6784\uff0c\u8fd9\u4e2afree\u94fe\u8868\u91cc\u6bcf\u4e2a\u8282\u70b9\u5c31\u662f\u4e00\u4e2a\u7a7a\u95f2\u7684\u7f13\u5b58\u9875\u7684\u5143\u6570\u636e\u5757\u5730\u5740\uff0c\u4e5f\u5c31\u662f\u8bf4\u53ea\u8981\u4e00\u4e2a\u7f13\u5b58\u9875\u662f\u7a7a\u95f2\u7684\uff0c\u90a3\u4e48\u4ed6\u7684\u5143\u6570\u636e\u5757\u5c31\u4f1a\u653e\u5165\u8fd9\u4e2afree\u94fe\u8868\u4e2d,\u8fd9\u6837\u52a0\u8f7d\u6570\u636e\u9875\u662f\u53ea\u9700\u8981\u4ecefree\u94fe\u8868\u4e2d\u627e\u7a7a\u95f2\u7684\u7f13\u5b58\u9875\u5373\u53ef\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmp\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4ece\u56fe\u4e2d\u5373\u53ef\u770b\u51fa\u94fe\u8868\u7684\u5927\u81f4\u7ed3\u6784\uff0c\u90a3\u4e48\u73b0\u5728\u6211\u4eec\u8981\u66f4\u65b0users\u8868\u4e2did=10\u7684\u8bb0\u5f55\uff0c\u9996\u5148\u8981\u77e5\u9053id=10\u8fd9\u6761\u8bb0\u5f55\u7684\u6570\u636e\u9875\u6709\u6ca1\u6709\u5728\u7f13\u5b58\u9875\u5f53\u4e2d\uff0c\u7136\u540e\u5728\u51b3\u5b9a\u662f\u5426\u662f\u52a0\u8f7d\u6570\u636e\u9875\u8fd8\u662f\u76f4\u63a5\u4f7f\u7528\u7f13\u5b58\u9875\uff0c\u6240\u4ee5\uff0cbuffer pool\u91cc\u8fd8\u6709\u5de6\u4e0b\u89d2\u8fd9\u79cdhash\u8868\uff0c\u7528\u8868\u7a7a\u95f4+\u6570\u636e\u9875\u53f7\u4f5c\u4e3akey\uff0c\u7f13\u5b58\u9875\u5730\u5740\u4e3avalue\uff0c\u53ef\u4ee5\u5feb\u901f\u5224\u65ad\u6570\u636e\u9875\u662f\u5426\u88ab\u7f13\u5b58\u3002<\/p>\n<p><strong>4.2.4 flush\u94fe\u8868<\/strong><\/p>\n<p>\u672c\u6587sql\u6267\u884c\u66f4\u65b0\u540e\uff0c\u8fd9\u6837\u5c31\u5bfc\u81f4\u5185\u5b58\u4e2d\u7684\u6570\u636e\u548c\u78c1\u76d8\u4e0a\u7684\u6570\u636e\u4e0d\u4e00\u81f4\uff0c\u8fd9\u5c31\u8868\u660e\u8fd9\u4e2a\u7f13\u5b58\u9875\u662f\u810f\u9875\uff0c\u810f\u9875\u662f\u9700\u8981\u5237\u65b0\u5230\u78c1\u76d8\u6587\u4ef6\u7684\u3002\u4f46\u662f\u4e0d\u53ef\u80fd\u6240\u6709\u7f13\u5b58\u9875\u90fd\u5237\u56de\u78c1\u76d8\uff0c\u6bd4\u5982\u6709\u7684\u7f13\u5b58\u9875\u53ef\u80fd\u53ea\u662f\u67e5\u8be2\u7684\u65f6\u5019\u7528\u5230\u4e86\uff0c\u6ca1\u6709\u522b\u66f4\u65b0\u8fc7\uff0c\u6240\u4ee5\u6570\u636e\u5e93\u5c31\u5f15\u5165flush\u94fe\u8868\uff0cflush\u94fe\u8868\u548cfree\u94fe\u8868\u7684\u5b9e\u73b0\u65b9\u5f0f\u4e00\u6837\uff0c\u90fd\u662f\u5728\u5143\u6570\u636e\u4e2d\u589e\u52a0\u4e24\u4e2a\u6307\u9488\u505a\u6210\u53cc\u5411\u94fe\u8868\uff0c\u7528\u6765\u6807\u8bb0\u94fe\u8868\u4e0a\u7684\u90fd\u662f\u810f\u9875\uff0c\u9700\u8981\u5237\u56de\u78c1\u76d8\uff0c\u540e\u7eedIO\u7ebf\u7a0b\u5f02\u6b65\u5237\u76d8\u5c31\u662f\u5c06flush\u94fe\u8868\u7684\u6570\u636e\u5237\u76d8\uff0c\u7136\u540e\u628a\u7f13\u5b58\u9875\u79fb\u9664flush\u94fe\u8868\uff0c\u52a0\u5165free\u94fe\u8868\u5f53\u4e2d\u3002<\/p>\n<p><strong>4.2.5 LRU\u94fe\u8868<\/strong><\/p>\n<p>\u968f\u7740\u4e0d\u505c\u7684\u628a\u78c1\u76d8\u4e0a\u7684\u6570\u636e\u9875\u52a0\u8f7d\u5230\u7a7a\u95f2\u7684\u7f13\u5b58\u9875\u91cc\u53bb\uff0cfree\u94fe\u8868\u4e2d\u7a7a\u95f2\u7684\u7f13\u5b58\u9875\u8d8a\u6765\u8d8a\u5c11\uff0c\u5982\u679cfree\u94fe\u8868\u7a7a\u4e86\uff0c\u8fd9\u65f6\u5019\u5c31\u65e0\u6cd5\u4ece\u78c1\u76d8\u52a0\u8f7d\u6570\u636e\u9875\u4e86\uff0c\u8fd9\u65f6\u5019\u5c31\u9700\u8981\u6dd8\u6c70\u6389\u4e00\u4e9b\u7f13\u5b58\u9875\uff0c\u9996\u5148\u60f3\u5230\u7684\u5c31\u662f\u628a\u4fee\u6539\u8fc7\u7684\u7f13\u5b58\u9875\u5237\u65b0\u56de\u78c1\u76d8\u4e0a\uff0c\u7136\u540e\u6e05\u7a7a\u8fd9\u4e2a\u7f13\u5b58\u9875<\/p>\n<p>\u5177\u4f53\u9009\u62e9\u54ea\u4e2a\u7f13\u5b58\u9875\u8fdb\u884c\u6e05\u7a7a\u5462\uff0c\u6570\u636e\u5e93\u5f15\u5165LRU\u94fe\u8868,\u7ed3\u6784\u548cfree\u94fe\u8868\u57fa\u672c\u4e00\u81f4,\u6700\u8fd1\u8bbf\u95ee\u7684\u7f13\u5b58\u9875\u90fd\u4f1a\u88ab\u79fb\u52a8\u5230LRU\u94fe\u8868\u7684\u5934\u90e8,\u8fd9\u6837\u5c3e\u90e8\u7684\u5c31\u662f\u5c11\u8bbf\u95ee\u7684\u6570\u636e\uff0c\u4f46\u662f\u8fd9\u6837\u7684LRU\u6709\u4e2a\u95ee\u9898\uff0c\u5c31\u662fMYSQL\u7684\u9884\u8bfb\u673a\u5236\uff0c\u4f1a\u628a\u4e0d\u5e38\u8bbf\u95ee\u6216\u8005\u4e0d\u8bbf\u95ee\u7684\u6570\u636e\u8fde\u5e26\u7740\u52a0\u8f7d\u5230\u5185\u5b58\uff0c\u8fd9\u6837\u5c31\u628a\u8fd9\u4e00\u90e8\u5206\u4e5f\u653e\u5728\u4e86LRU\u5934\u7ed3\u70b9\u4e0a\uff0c\u5f88\u660e\u663e\u4e0d\u5408\u7406,\u540c\u7406\uff0c\u5168\u8868\u626b\u63cf\u4e5f\u6709\u8fd9\u4e2a\u95ee\u9898\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmq\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4ece\u4e0a\u9762\u53ef\u4ee5\u770b\u51fa\uff0c\u5982\u679c\u6b64\u65f6\u9700\u8981\u6dd8\u6c70\u7f13\u5b58\u9875\uff0c\u5c31\u53ef\u80fd\u628a\u70ed\u70b9\u6570\u636e\u63d0\u524d\u6dd8\u6c70\u6389\u3002\u5bf9\u4e8e\u8fd9\u79cd\u4e0d\u5408\u7406\u7684LRU\u7b97\u6cd5MYSQL\u57fa\u4e8e\u51b7\u70ed\u6570\u636e\u5206\u79bb\u7684\u65b9\u6cd5\u5bf9LRU\u7b97\u6cd5\u8fdb\u884c\u5982\u4e0b\u4f18\u5316\uff1aLRU\u94fe\u8868\u88ab\u62c6\u5206\u4e3a\u4e24\u4e2a\u90e8\u5206\uff0c\u4e00\u90e8\u5206\u70ed\u6570\u636e\uff0c\u4e00\u90e8\u5206\u51b7\u6570\u636e\uff0c\u6570\u636e\u9875\u7b2c\u4e00\u6b21\u52a0\u8f7d\u5230\u7f13\u5b58\u7684\u65f6\u5019\u662f\u653e\u5728\u51b7\u6570\u636e\u8868\u5934\uff0c\u57281s\u540e\u518d\u6b21\u8bbf\u95ee\u8fd9\u4e2a\u7f13\u5b58\u9875\uff0c\u5c31\u5f88\u6709\u53ef\u80fd\u662f\u70ed\u6570\u636e\uff0c\u5c31\u4f1a\u628a\u5b83\u632a\u5230\u70ed\u6570\u636e\u8868\u5934\u533a\u57df\uff0c\u8fd9\u6837\u8bbe\u8ba1\u9632\u6b62\u4e86\u521a\u52a0\u8f7d\u5c31\u8bbf\u95ee\u9020\u6210\u7684\u5047\u70ed\u73b0\u8c61\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmr\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u51b7\u70ed\u533a\u57df\u7f13\u5b58\u9875\u79fb\u52a8\u89c4\u5219\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>\u51b7\u6570\u636e -&gt; \u70ed\u6570\u636e<\/li>\n<li>\u51b7\u6570\u636e\u533a\u7684\u7f13\u5b58\u9875\u662f\u5728 1s \u540e\u518d\u88ab\u8bbf\u95ee\u5230\u5c31\u79fb\u52a8\u5230\u70ed\u6570\u636e\u533a\u7684\u94fe\u8868\u5934\u90e8<\/li>\n<li>\u70ed\u6570\u636e -&gt; \u51b7\u6570\u636e<\/li>\n<li>\u80fd\u7559\u5728\u70ed\u6570\u636e\u533a\u57df\u7684\u7f13\u5b58\u9875\uff0c\u8bc1\u660e\u90fd\u662f\u7f13\u5b58\u547d\u4e2d\u7387\u6bd4\u8f83\u9ad8\u7684\uff0c\u4f1a\u7ecf\u5e38\u88ab\u8bbf\u95ee\u5230\u3002\u5982\u679c\u6bcf\u4e2a\u7f13\u5b58\u9875\u88ab\u8bbf\u95ee\u90fd\u79fb\u52a8\u5230\u94fe\u8868\u5934\u90e8\uff0c\u90a3\u8fd9\u4e2a\u64cd\u4f5c\u5c06\u4f1a\u975e\u5e38\u7684\u9891\u7e41\u3002\u6240\u4ee5 InnoDB \u5b58\u50a8\u5f15\u64ce\u505a\u4e86\u4e00\u4e2a\u4f18\u5316\uff0c\u53ea\u6709\u5728\u70ed\u6570\u636e\u533a\u57df\u7684\u540e 3\/4 \u7684\u7f13\u5b58\u9875\u88ab\u8bbf\u95ee\u4e86\uff0c\u624d\u4f1a\u79fb\u52a8\u5230\u94fe\u8868\u5934\u90e8\uff1b\u5982\u679c\u662f\u70ed\u6570\u636e\u533a\u57df\u7684\u524d 1\/4 \u7684\u7f13\u5b58\u9875\u88ab\u8bbf\u95ee\u5230\uff0c\u5b83\u662f\u4e0d\u4f1a\u88ab\u79fb\u52a8\u5230\u94fe\u8868\u5934\u90e8\u53bb\u7684\u3002\u8fd9\u6837\u5c3d\u53ef\u80fd\u7684\u51cf\u5c11\u94fe\u8868\u4e2d\u8282\u70b9\u7684\u79fb\u52a8\u4e86<\/li>\n<\/ul>\n<p><strong>4.2.6 \u5c0f\u7ed3<\/strong><\/p>\n<p>\u73b0\u5728\u6211\u4eec\u4e86\u89e3\u4e86\u66f4\u65b0\u6570\u636e\u4f1a\u5148\u628a\u6570\u636e\u52a0\u8f7d\u8fdbbuffer pool\u5728\u8fdb\u884c\uff0c\u4e86\u89e3buffer pool\u662f\u5982\u4f55\u901a\u8fc7\u51b7\u70ed\u6570\u636e\u5206\u79bb\u7684\u673a\u5236\u4f18\u5316LRU\u94fe\u8868\uff0c\u4e3a\u7cfb\u7edf\u8bbe\u8ba1\u4e2d\u7f13\u5b58\u8fc7\u671f\u6dd8\u6c70\u7b56\u7565\u63d0\u4f9b\u7684\u65b0\u7684\u89e3\u51b3\u601d\u8def\u3002\u65e2\u7136\uff0c\u6570\u636e\u66f4\u65b0\u662f\u628a\u6570\u636e\u8f7d\u5165buffer pool\u4e2d\u4fee\u6539\uff0c\u90a3\u4e48\u66f4\u65b0\u5b8c\u7f13\u5b58\u9875\u4e4b\u540e\u6570\u636e\u5e93\u662f\u5982\u4f55\u4fdd\u8bc1\u4e8b\u52a1\u63d0\u4ea4\u3001\u5982\u4f55\u4fdd\u8bc1\u6570\u636e\u9875\u548c\u7f13\u5b58\u9875\u6570\u636e\u4e00\u81f4\u7684\u5462<\/p>\n<p><strong>4.3 undo log<\/strong><\/p>\n<p>\u8bf4\u5230\u4e8b\u52a1\u5c31\u4e0d\u5f97\u4e0d\u63d0\u4e8b\u52a1\u662f\u5982\u4f55\u56de\u6eda\u7684\uff0cinnodb\u662f\u5f15\u5165\u4e86undo log\u7684\u65e5\u5fd7\u7ec4\u4ef6\u6765\u5b9e\u73b0\u4e8b\u52a1\u56de\u6eda\u7684\uff0c\u4ee5\u672c\u6587sql\u4e3a\u4f8b, \u5728\u6570\u636e\u52a0\u8f7d\u8fdb\u7f13\u5b58\u9875\u540e\uff0c\u4fee\u6539\u4e4b\u524d\uff0c\u4f1a\u5c06\u6267\u884c\u7684sql\u53d6\u53cd\u4fdd\u5b58\u5728undo log\u4e2d\uff0c\u903b\u8f91\u7c7b\u4f3csql\uff1a<\/p>\n<p>update users set name=\u2019lisi\u2019 where id = 10<\/p>\n<p>\u5f53\u7136\u5982\u679c\u662finsert\u8bed\u53e5\u4e0e\u4e4b\u5bf9\u5e94\u7684\u5c31\u662fdelete\u8bed\u53e5\uff0cdelete\u8bed\u53e5\u4e5f\u5c31\u5bf9\u5e94\u7684insert \u8bed\u53e5\uff0c\u8fd9\u4e5f\u5c31\u660e\u767d\u4e3a\u4ec0\u4e48delete\u7684\u6570\u636e\u662f\u53ef\u4ee5\u56de\u6eda\uff0c\u800ctruncate\u6570\u636e\u4e4b\u540e\u65e0\u6cd5\u56de\u6eda\u7684\u6839\u672c\u539f\u56e0\uff0c\u5728\u4e8etruncate\u65e0\u6cd5\u751f\u6210undo log\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zms\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u4e0a\u56fe\u662f\u672c\u95eesql\u6267\u884c\u7684\u5927\u81f4\u6b65\u9aa4\uff0c\u81f3\u4e8e\u52a0\u5165buffer pool\u8fd9\u5757\u4e0a\u6587\u5df2\u7ecf\u8be6\u7ec6\u4e86\u89e3\u8fc7\u4e86\uff0c\u5c31\u4e0d\u5728\u8d58\u8ff0\u3002\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u51fa\u56e0\u4e3alog\u76f4\u63a5\u5237\u76d8\u6bd4\u8f83\u635f\u8017\u6027\u80fd\uff0c\u6240\u4ee5\u5f15\u5165log buffer\u8fdb\u884c\u7f13\u5b58\uff0c\u7136\u540e\u5728\u901a\u8fc7\u5f02\u6b65\u7684\u65b9\u5f0f\u628a\u6570\u636e\u5237\u5165\u78c1\u76d8\u65e2\u7136\u6570\u636e\u66f4\u65b0\u4e4b\u524d\u7684\u6570\u636e\u8bb0\u5f55\u4e0b\u6765\u5e76\u6210\u529f\u5237\u5165\u78c1\u76d8\uff0c\u5219\u4e8b\u52a1\u7684\u56de\u6eda\u5c31\u4e0d\u96be\u5b9e\u73b0\u4e86\u3002<\/p>\n<p>\u5f53\u7136undo log \u9664\u4e86\u63d0\u4f9b\u56de\u6eda\u529f\u80fd\uff0c\u8fd8\u4e3a\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\uff08MVCC\uff09\u63d0\u4f9b\u4e86\u5b9e\u73b0\u57fa\u7840\uff0c\u5b9e\u73b0\u4e86MYSQL\u7684\u975e\u963b\u585e\u8bfb\u5199\uff0c\u63d0\u9ad8\u4e86\u7cfb\u7edf\u7684\u5e76\u53d1\u6027\u3002\u672c\u6587\u4e5f\u4e0d\u518d\u6df1\u5165<\/p>\n<p><strong>4.4 redo log<\/strong><\/p>\n<p>\u4e0b\u9762\u6765\u4e86\u89e3\u4e00\u4e0binnodb\u662f\u5982\u4f55\u4fdd\u8bc1buffer pool\u7f13\u5b58\u7684\u6570\u636e\u4e00\u81f4\u6027\u95ee\u9898\uff0c\u6570\u636e\u66f4\u65b0\u503c\u5185\u5b58\u540e\u5e76\u4e0d\u4f1a\u7acb\u5373\u5237\u65b0\u81f3\u78c1\u76d8\u6570\u636e\u9875\uff0c\u800c\u662f\u4e00\u81f4\u4ee5\u810f\u9875\u7684\u5f62\u5f0f\u4fdd\u5b58\u5728buffer pool\u5f53\u4e2d\uff0c\u8fd9\u6837\u505a\u6709\u4e24\u4e2a\u539f\u56e0\u4f1a\u5bfc\u81f4\u6548\u7387\u5f88\u5dee\uff0c\u4e00\u4e2a\u662f\u5185\u5b58\u5411\u78c1\u76d8\u5199\u6570\u636e\u672c\u8eab\u6548\u7387\u5c31\u6162\uff0c\u53e6\u4e00\u4e2a\u5c31\u662f\u968f\u673aIO\u4f1a\u5199\u78c1\u76d8\u7684\u65f6\u95f4\u4e0a\u9644\u52a0\u4e0a\u5f88\u591a\u78c1\u5934\u5bfb\u5740\u7684\u65f6\u95f4\uff0c\u6240\u4ee5\u7acb\u5373\u5237\u6570\u636e\u9875\u6548\u7387\u5f88\u4f4e\u3002<\/p>\n<p>Innodb\u662f\u5982\u4f55\u89c4\u907f\u4e0a\u8ff0\u95ee\u9898\u7684\u5462\uff0c\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u5f02\u6b65\u5237\u76d8\u5c31\u5df2\u7ecf\u53ef\u4ee5\u89e3\u51b3\u4e86\u5237\u78c1\u76d8\u6162\u7684\u95ee\u9898\uff0c\u4f46\u662f\uff0c\u5047\u5982MYSQL\u7cfb\u7edf\u5d29\u6e83\u3001\u5b95\u673a\uff0c\u8fd9\u65f6\u5019\u810f\u9875\u8fd8\u672a\u53ca\u65f6\u5237\u76d8\uff0c\u90a3\u4e48\u7f13\u5b58\u9875\u671f\u95f4\u6240\u6709\u6539\u52a8\u6570\u636e\u5c82\u4e0d\u662f\u4e22\u4e86\uff0c\u6240\u4ee5\uff0cInnodb\u5f15\u5165\u4e86\u53e6\u4e00\u4e2a\u7ec4\u4ef6redo log\uff0c\u4e13\u95e8\u8bb0\u5f55\u6570\u636e\u88ab\u7f13\u5b58\u671f\u95f4\u505a\u8fc7\u7684\u4fee\u6539\u8bb0\u5f55\uff0c\u7136\u540e\u7acb\u5373\u5199\u5165redo log\u78c1\u76d8\u6587\u4ef6\uff0c\u76f8\u6bd4\u4e8e\u7f13\u5b58\u9875\u5237\u76d8\uff0credo log\u5237\u76d8\u7684\u6570\u636e\u4e86\u5c0f\u591a\u4e86\uff0c\u5e76\u4e14\u5199redo log\u662f\u987a\u5e8fIO\uff0c\u800c\u7f13\u5b58\u9875\u5237\u76d8\u662f\u968f\u673aIO\u3002\u4e0b\u56fe\u793a\u610f\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmt\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u8fd9\u6837\u5f53\u6570\u636e\u5e93\u5f02\u5e38\u5b95\u673a\u65f6\uff0c\u5373\u4f7f\u7f13\u5b58\u9875\u4e22\u5931\u6570\u636e\u4e5f\u4e0d\u4f1a\u4e22\u5931\uff0c\u56e0\u4e3aredo log\u5df2\u7ecf\u843d\u76d8\uff0c\u6570\u636e\u5e93\u91cd\u542f\u7684\u65f6\u5019\u4f1a\u66f4\u8fd1redo log\u628a\u78c1\u76d8\u4e0a\u5386\u53f2\u7684\u6570\u636e\u9875\u91cd\u65b0\u8f7d\u5165\u5185\u5b58\uff0c\u91cd\u65b0\u6309redo log\u7684\u4fee\u6539\u8bb0\u5f55\u64cd\u4f5c\u4e00\u904d\u5c31\u80fd\u5c06\u7f13\u5b58\u9875\u4e2d\u7684\u6570\u636e\u6062\u590d\u81f3\u5b95\u673a\u524d\u7684\u72b6\u6001\u3002<\/p>\n<p>\u5982\u679c\u7cfb\u7edf\u5b95\u673a\u65f6\uff0credo log\u8fd8\u6ca1\u843d\u76d8\u6570\u636e\u5c82\u4e0d\u662f\u4e22\u4e86\uff0c\u5bf9\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\u6570\u636e\u4f1a\u4e22\uff0c\u8fd9\u79cdredo log\u4e22\u6570\u636e\u5206\u4e24\u4e2d\u60c5\u51b5\uff1a<\/p>\n<p>\u7b2c\u4e00\u79cd\u60c5\u51b5\uff0cMYSQL\u6709\u4e09\u79cd\u5237\u76d8\u7b56\u7565\uff0c\u901a\u8fc7innodb_flush_log_at_trx_commit\u53c2\u6570\u8fdb\u884c\u914d\u7f6e<\/p>\n<ol>\n<li>\u914d\u7f6e\u4e3a0\uff1a\u4e8b\u52a1\u63d0\u4ea4\u7684\u65f6\u5019\u4e0d\u4f1a\u628aredolog buffer\u91cc\u7684\u6570\u636e\u7acb\u5373\u5237\u5165\u78c1\u76d8\uff0c\u6b64\u65f6\u5982\u679c\u5b95\u673a\u5219\u4f1a\u5bfc\u81f4\u5df2\u63d0\u4ea4\u7684\u6570\u636e\u4fee\u6539\u4e22\u5931\uff1b<\/li>\n<li>\u914d\u7f6e\u4e3a1\uff1a\u5219\u662f\u4e8b\u52a1\u63d0\u4ea4\u7684\u65f6\u5019\u5fc5\u987b\u628aredolog buffer\u91cc\u7684\u6570\u636e\u5237\u5165\u78c1\u76d8\uff0c\u4ee5\u4fdd\u8bc1\u4e8b\u52a1\u63d0\u4ea4\u540e\u64cd\u4f5c\u6570\u636e\u65e5\u5fd7\u4e0d\u4e22\uff1b<\/li>\n<li>\u914d\u7f6e\u4e3a2\uff1a\u5219\u8868\u793a\u53ea\u662f\u628a\u6570\u636e\u4ea4\u7ed9\u64cd\u4f5c\u7cfb\u7edf\u8fdb\u884c\u5237\u76d8\uff0c\u64cd\u4f5c\u7cfb\u7edf\u5237\u6ca1\u5237\u6210\u529f\u5219\u4e0d\u7ba1\uff0c\u7406\u8bba\u4e0a\u64cd\u4f5c\u7cfb\u7edf\u5237\u76d8\u662f\u5148\u8981\u7ecf\u8fc7os cache\u5185\u5b58\u7f13\u5b58\u7684\uff0c\u5c31\u662f\u8bf4\u6570\u636e\u4f1a\u5148\u5728os chache\u91cc\u6ca1\u6709\u771f\u6b63\u7684\u843d\u76d8\uff0c\u8fd9\u79cd\u6a21\u5f0f\u4e0b\u4e5f\u53ef\u80fd\u5bfc\u81f4\u6570\u636e\u4e22\u5931<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmu\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/li>\n<\/ol>\n<p>\u8fd9\u7b2c\u4e00\u79cd\u60c5\u51b5\u5982\u679c\u4ea7\u751f\u4e22\u6570\u636e\uff0c\u662f\u771f\u7684\u4e22\u5931\uff0c\u6240\u4ee5\uff0c\u5982\u679c\u5bf9\u6570\u636e\u5e93\u4e22\u5931\u6570\u636e\u96f6\u5bb9\u5fcd\uff0c\u5efa\u8bae\u914d\u7f6e\u7b56\u7565\u4e3a1<\/p>\n<p>\u7b2c\u4e8c\u79cd\u60c5\u51b5\uff0c\u5c31\u662f\u672a\u5199commit\u6807\u8bb0\u65e5\u5fd7\u7684\u60c5\u51b5\uff0c\u5373\u4e0b\u56fe\u7b2c9\u6b65\u4e22\u5931\u7684\u60c5\u51b5\uff0c\u4f46\u662f\u8fd9\u79cd\u60c5\u51b5\u7cfb\u7edf\u8ba4\u4e3a\u4e8b\u52a1\u63d0\u4ea4\u5931\u8d25\uff0c\u6240\u4ee5\u4e22\u5931\u4e86\u5e76\u4e0d\u5f71\u54cd\u6570\u636e\u4e00\u81f4\u6027\u3002<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/bVc2zmv\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u56fe\u4e2d7\u30018\u30019\u4e09\u4e2a\u6b65\u9aa4\u662f\u4e8b\u52a1\u63d0\u4ea4commit\u7684\u65f6\u5019\u624d\u505a\u7684\uff08\u672c\u6587\u53ea\u7528\u4e00\u4e2asql\u6765\u8bb2\u89e3\uff0c\u9ed8\u8ba4\u4e8b\u52a1\u81ea\u52a8\u63d0\u4ea4\uff09\uff0credo log\u8bb0\u5f55\u66f4\u65b0\u8bb0\u5f55\u4e4b\u540e\uff0c\u6267\u884c\u5668\u4f1a\u628a\u4fee\u6539\u8bb0\u5f55\u5199\u5728server\u5c42\u7684binlog\u5f53\u4e2d\uff0c\u5f88\u660e\u663e\u8fd9\u662f\u4e24\u4e2a\u6587\u4ef6\uff0c\u5982\u679c\u51fa\u73b0\u4e0a\u8ff0\u5b95\u673a\u7b49\u5f02\u5e38\u60c5\u51b5\uff0c\u8fd9\u4e24\u4e2a\u6587\u4ef6\u7684\u6570\u636e\u4e00\u81f4\u6027\u662f\u4e0d\u80fd\u4fdd\u8bc1\u7684\uff0c\u6240\u4ee5\uff0c\u4e3a\u4e86\u4fdd\u8bc1\u4e24\u4e2a\u6587\u4ef6\u7684\u6570\u636e\u4e00\u81f4\u6027\uff0cinnodb\u4f1a\u5728binlog\u5199\u5b8c\u4e4b\u540e\u5728redo log\u4e2d\u8865\u4e0a\u4e00\u4e2acommit\u6807\u8bb0\u544a\u8bc9redo log\u4e8b\u52a1\u6210\u529f\u3002\u4e8b\u52a1\u6267\u884c\u6210\u529f\u540e\u64cd\u4f5credo log\u5237\u5165\u78c1\u76d8\uff0c\u81f3\u6b64\u672c\u6587sql\u6267\u884c\u6210\u529f\u3002<\/p>\n<p><strong>5 \u603b\u7ed3<\/strong><br \/>\u901a\u8fc7\u4e00\u6761update\u7684sql\u7684\u66f4\u65b0\u6d41\u7a0b\uff0c\u6e05\u6670\u7684\u770b\u5230MYSQL\u7684\u6574\u4f53\u67b6\u6784\u8bbe\u8ba1\uff0c\u5bf9Innodb\u5b58\u50a8\u5f15\u64ce\u7684\u51e0\u5927\u6838\u5fc3\u7ec4\u4ef6\u5982\u4f55\u76f8\u4e92\u534f\u4f5c\u3001\u914d\u5408\u4ee5\u5b9e\u73b0\u9ad8\u6548\u7684\u6570\u636e\u5e93\u7cfb\u7edf\u6709\u4e86\u66f4\u6e05\u6670\u7684\u8ba4\u8bc6\uff1b\u6838\u5fc3\u7ec4\u4ef6buffer pool\u7684\u51b7\u70ed\u6570\u636e\u5206\u79bb\u7684\u7f13\u5b58\u6dd8\u6c70\u673a\u5236\u4e5f\u4e3a\u4ee5\u540e\u7cfb\u7edf\u7684\u67b6\u6784\u8bbe\u8ba1\u63d0\u4f9b\u4e86\u65b0\u7684\u89e3\u51b3\u601d\u8def\u3002<\/p>\n<p>\u4f5c\u8005\uff1a\u9646\u5e86\u6797<\/p>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000042519251\">https:\/\/segmentfault.com\/a\/1190000042519251<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>1 \u524d\u8a00\u5bf9\u4e8e\u4e00\u4e2a\u670d\u52a1\u7aef\u5f00\u53d1\u6765\u8bf4 MYSQL \u53ef\u80fd\u662f\u4ed6\u4f7f\u7528\u6700\u719f\u6089\u7684\u6570\u636e\u5e93\u5de5\u5177\uff0c\u7136\u800c\uff0c\u5927\u90e8\u5206\u7684Java\u5de5\u7a0b\u5e08\u5bf9My [&hellip;]<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[],"tags":[],"class_list":["post-10006559","post","type-post","status-publish","format-standard","hentry"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10006559","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10006559"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10006559\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10006559"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10006559"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10006559"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}