{"id":4926,"date":"2020-03-25T18:33:53","date_gmt":"2020-03-25T10:33:53","guid":{"rendered":"https:\/\/www.xttblog.com\/?p=4926"},"modified":"2020-03-25T18:33:53","modified_gmt":"2020-03-25T10:33:53","slug":"mysql-innodb-%e7%9a%84%e5%8a%a0%e9%94%81%e5%88%86%e6%9e%90","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=4926","title":{"rendered":"MySQL InnoDB \u7684\u52a0\u9501\u5206\u6790"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u524d\u9762\u5199\u4e86\u4e00\u7bc7 MySQL \u7684 2PL \u6587\u7ae0\u300a<a href=\"https:\/\/mp.weixin.qq.com\/s\/pXQEtOuy9ejXcN-D710-wA\">8 \u5f20\u56fe\uff0c\u7ed9\u4f60\u5b8c\u6574\u7684\u5256\u6790 MySQL \u4e24\u9636\u6bb5\u52a0\u9501\uff082PL\uff09\u534f\u8bae<\/a>\u300b\uff0c\u7fa4\u91cc\u6709\u4eba@\u6211\u5173\u4e8e MySQL \u7684\u52a0\u9501\u95ee\u9898\uff0c\u4e8b\u5b9e\u4e0a MySQL \u7684\u52a0\u9501\u8fc7\u7a0b\u975e\u5e38\u7684\u590d\u6742\uff0c2PL \u53ea\u662f\u4e00\u4e2a\u6700\u7b80\u5355\uff0c\u6700\u5bb9\u6613\u7406\u89e3\u7684\u4e00\u4e2a\uff01\u4eca\u5929\uff0c\u518d\u4ecb\u7ecd\u51e0\u79cd\u52a0\u9501\u7684\u601d\u8def\uff0c\u5982\u6709\u8bef\u5ffd\u55b7\uff01\u63a8\u8350\u5927\u5bb6\u9605\u8bfb\u9ad8\u6027\u80fd MySQL\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">\u80cc\u666f<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">MySQL\/InnoDB\u7684\u52a0\u9501\u5206\u6790\uff0c\u4e00\u76f4\u662f\u4e00\u4e2a\u6bd4\u8f83\u56f0\u96be\u7684\u8bdd\u9898\u3002\u6211\u5728\u5de5\u4f5c\u8fc7\u7a0b\u4e2d\uff0c\u7ecf\u5e38\u4f1a\u6709\u540c\u4e8b\u54a8\u8be2\u8fd9\u65b9\u9762\u7684\u95ee\u9898\u3002\u540c\u65f6\uff0c\u5fae\u535a\u4e0a\u4e5f\u7ecf\u5e38\u4f1a\u6536\u5230MySQL\u9501\u76f8\u5173\u7684\u79c1\u4fe1\uff0c\u8ba9\u6211\u5e2e\u52a9\u89e3\u51b3\u4e00\u4e9b\u6b7b\u9501\u7684\u95ee\u9898\u3002\u672c\u6587\uff0c\u51c6\u5907\u5c31MySQL\/InnoDB\u7684\u52a0\u9501\u95ee\u9898\uff0c\u5c55\u5f00\u8f83\u4e3a\u6df1\u5165\u7684\u5206\u6790\u4e0e\u8ba8\u8bba\uff0c\u4e3b\u8981\u662f\u4ecb\u7ecd\u4e00\u79cd\u601d\u8def\uff0c\u8fd0\u7528\u6b64\u601d\u8def\uff0c\u62ff\u5230\u4efb\u4f55\u4e00\u6761SQL\u8bed\u53e5\uff0c\u90fd\u80fd\u5b8c\u6574\u7684\u5206\u6790\u51fa\u8fd9\u6761\u8bed\u53e5\u4f1a\u52a0\u4ec0\u4e48\u9501\uff1f\u4f1a\u6709\u4ec0\u4e48\u6837\u7684\u4f7f\u7528\u98ce\u9669\uff1f\u751a\u81f3\u662f\u5206\u6790\u7ebf\u4e0a\u7684\u4e00\u4e2a\u6b7b\u9501\u573a\u666f\uff0c\u4e86\u89e3\u6b7b\u9501\u4ea7\u751f\u7684\u539f\u56e0\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>\u6ce8\uff1aMySQL\u662f\u4e00\u4e2a\u652f\u6301\u63d2\u4ef6\u5f0f\u5b58\u50a8\u5f15\u64ce\u7684\u6570\u636e\u5e93\u7cfb\u7edf\u3002\u672c\u6587\u4e0b\u9762\u7684\u6240\u6709\u4ecb\u7ecd\uff0c\u90fd\u662f\u57fa\u4e8eInnoDB\u5b58\u50a8\u5f15\u64ce\uff0c\u5176\u4ed6\u5f15\u64ce\u7684\u8868\u73b0\uff0c\u4f1a\u6709\u8f83\u5927\u7684\u533a\u522b\u3002<\/p><\/blockquote>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"mvcc\">\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236 MVCC<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">MySQL InnoDB \u5b58\u50a8\u5f15\u64ce\uff0c\u5b9e\u73b0\u7684\u662f\u57fa\u4e8e\u591a\u7248\u672c\u7684\u5e76\u53d1\u63a7\u5236\u534f\u8bae MVCC (Multi-Version Concurrency Control) \uff0c\u4e0e MVCC \u76f8\u5bf9\u7684\uff0c\u662f\u57fa\u4e8e\u9501\u7684\u5e76\u53d1\u63a7\u5236\uff0cLock-Based Concurrency Control\u3002MVCC \u6700\u5927\u7684\u597d\u5904\uff0c\u76f8\u4fe1\u4e5f\u662f\u8033\u719f\u80fd\u8be6\uff1a\u8bfb\u4e0d\u52a0\u9501\uff0c\u8bfb\u5199\u4e0d\u51b2\u7a81\u3002\u5728\u8bfb\u591a\u5199\u5c11\u7684 OLTP \u5e94\u7528\u4e2d\uff0c\u8bfb\u5199\u4e0d\u51b2\u7a81\u662f\u975e\u5e38\u91cd\u8981\u7684\uff0c\u6781\u5927\u7684\u589e\u52a0\u4e86\u7cfb\u7edf\u7684\u5e76\u53d1\u6027\u80fd\uff0c\u8fd9\u4e5f\u662f\u4e3a\u4ec0\u4e48\u73b0\u9636\u6bb5\uff0c\u51e0\u4e4e\u6240\u6709\u7684 RDBMS\uff0c\u90fd\u652f\u6301\u4e86 MVCC\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 MVCC \u5e76\u53d1\u63a7\u5236\u4e2d\uff0c\u8bfb\u64cd\u4f5c\u53ef\u4ee5\u5206\u6210\u4e24\u7c7b\uff1a\u5feb\u7167\u8bfb (snapshot read)\u4e0e\u5f53\u524d\u8bfb (current read)\u3002\u5feb\u7167\u8bfb\uff0c\u8bfb\u53d6\u7684\u662f\u8bb0\u5f55\u7684\u53ef\u89c1\u7248\u672c (\u6709\u53ef\u80fd\u662f\u5386\u53f2\u7248\u672c)\uff0c\u4e0d\u7528\u52a0\u9501\u3002\u5f53\u524d\u8bfb\uff0c\u8bfb\u53d6\u7684\u662f\u8bb0\u5f55\u7684\u6700\u65b0\u7248\u672c\uff0c\u5e76\u4e14\uff0c\u5f53\u524d\u8bfb\u8fd4\u56de\u7684\u8bb0\u5f55\uff0c\u90fd\u4f1a\u52a0\u4e0a\u9501\uff0c\u4fdd\u8bc1\u5176\u4ed6\u4e8b\u52a1\u4e0d\u4f1a\u518d\u5e76\u53d1\u4fee\u6539\u8fd9\u6761\u8bb0\u5f55\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e00\u4e2a\u652f\u6301 MVCC \u5e76\u53d1\u63a7\u5236\u7684\u7cfb\u7edf\u4e2d\uff0c\u54ea\u4e9b\u8bfb\u64cd\u4f5c\u662f\u5feb\u7167\u8bfb\uff1f\u54ea\u4e9b\u64cd\u4f5c\u53c8\u662f\u5f53\u524d\u8bfb\u5462\uff1f\u4ee5 MySQL InnoDB \u4e3a\u4f8b\uff0c\u770b\u4e0b\u9762\u7684\u4f8b\u5b50\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5feb\u7167\u8bfb\uff1a\u7b80\u5355\u7684select\u64cd\u4f5c\uff0c\u5c5e\u4e8e\u5feb\u7167\u8bfb\uff0c\u4e0d\u52a0\u9501\u3002(\u5f53\u7136\uff0c\u4e5f\u6709\u4f8b\u5916\uff0c\u4e0b\u9762\u4f1a\u5206\u6790)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select * from table where ?;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u524d\u8bfb\uff1a\u7279\u6b8a\u7684\u8bfb\u64cd\u4f5c\uff0c\u63d2\u5165\/\u66f4\u65b0\/\u5220\u9664\u64cd\u4f5c\uff0c\u5c5e\u4e8e\u5f53\u524d\u8bfb\uff0c\u9700\u8981\u52a0\u9501\u3002\u3000\u3000<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\"><code>select * from table where ? lock in share mode;<\/code><code>select * from table where ? for update;<\/code><code>insert into table values (\u2026);<\/code><code>update table set ? where ?;<\/code><code>delete from table where ?;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0a\u9762\u7684 5 \u4e2a\u8bed\u53e5\uff0c\u90fd\u5c5e\u4e8e\u5f53\u524d\u8bfb\uff0c\u8bfb\u53d6\u8bb0\u5f55\u7684\u6700\u65b0\u7248\u672c\u3002\u5e76\u4e14\uff0c\u8bfb\u53d6\u4e4b\u540e\uff0c\u8fd8\u9700\u8981\u4fdd\u8bc1\u5176\u4ed6\u5e76\u53d1\u4e8b\u52a1\u4e0d\u80fd\u4fee\u6539\u5f53\u524d\u8bb0\u5f55\uff0c\u5bf9\u8bfb\u53d6\u8bb0\u5f55\u52a0\u9501\u3002\u5176\u4e2d\uff0c\u9664\u4e86\u7b2c\u4e00\u6761\u8bed\u53e5\uff0c\u5bf9\u8bfb\u53d6\u8bb0\u5f55\u52a0 S \u9501 (\u5171\u4eab\u9501)\u5916\uff0c\u5176\u4ed6\u7684\u64cd\u4f5c\uff0c\u90fd\u52a0\u7684\u662f X \u9501 (\u6392\u5b83\u9501)\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4ec0\u4e48\u5c06 \u63d2\u5165\/\u66f4\u65b0\/\u5220\u9664 \u64cd\u4f5c\uff0c\u90fd\u5f52\u4e3a\u5f53\u524d\u8bfb\uff1f\u53ef\u4ee5\u770b\u770b\u4e0b\u9762\u8fd9\u4e2a \u66f4\u65b0 \u64cd\u4f5c\uff0c\u5728\u6570\u636e\u5e93\u4e2d\u7684\u6267\u884c\u6d41\u7a0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585116992939.jpg\" alt=\"update \u4e3a\u4ec0\u4e48\u662f\u5f53\u524d\u8bfb\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ece\u4e0a\u56fe\u4e2d\uff0c\u53ef\u4ee5\u770b\u5230\uff0c\u4e00\u4e2a Update \u64cd\u4f5c\u7684\u5177\u4f53\u6d41\u7a0b\u3002\u5f53 Update SQL \u88ab\u53d1\u7ed9 MySQL \u540e\uff0cMySQL Server \u4f1a\u6839\u636e where \u6761\u4ef6\uff0c\u8bfb\u53d6\u7b2c\u4e00\u6761\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\uff0c\u7136\u540e InnoDB \u5f15\u64ce\u4f1a\u5c06\u7b2c\u4e00\u6761\u8bb0\u5f55\u8fd4\u56de\uff0c\u5e76\u52a0\u9501 (current read)\u3002\u5f85 MySQL Server \u6536\u5230\u8fd9\u6761\u52a0\u9501\u7684\u8bb0\u5f55\u4e4b\u540e\uff0c\u4f1a\u518d\u53d1\u8d77\u4e00\u4e2a Update \u8bf7\u6c42\uff0c\u66f4\u65b0\u8fd9\u6761\u8bb0\u5f55\u3002\u4e00\u6761\u8bb0\u5f55\u64cd\u4f5c\u5b8c\u6210\uff0c\u518d\u8bfb\u53d6\u4e0b\u4e00\u6761\u8bb0\u5f55\uff0c\u76f4\u81f3\u6ca1\u6709\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u4e3a\u6b62\u3002\u56e0\u6b64\uff0cUpdate \u64cd\u4f5c\u5185\u90e8\uff0c\u5c31\u5305\u542b\u4e86\u4e00\u4e2a\u5f53\u524d\u8bfb\u3002\u540c\u7406\uff0cDelete \u64cd\u4f5c\u4e5f\u4e00\u6837\u3002Insert \u64cd\u4f5c\u4f1a\u7a0d\u5fae\u6709\u4e9b\u4e0d\u540c\uff0c\u7b80\u5355\u6765\u8bf4\uff0c\u5c31\u662f Insert \u64cd\u4f5c\u53ef\u80fd\u4f1a\u89e6\u53d1 Unique Key \u7684\u51b2\u7a81\u68c0\u67e5\uff0c\u4e5f\u4f1a\u8fdb\u884c\u4e00\u4e2a\u5f53\u524d\u8bfb\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>\u6ce8\uff1a\u6839\u636e\u4e0a\u56fe\u7684\u4ea4\u4e92\uff0c\u9488\u5bf9\u4e00\u6761\u5f53\u524d\u8bfb\u7684 SQL \u8bed\u53e5\uff0cInnoDB \u4e0e MySQL Server \u7684\u4ea4\u4e92\uff0c\u662f\u4e00\u6761\u4e00\u6761\u8fdb\u884c\u7684\uff0c\u56e0\u6b64\uff0c\u52a0\u9501\u4e5f\u662f\u4e00\u6761\u4e00\u6761\u8fdb\u884c\u7684\u3002\u5148\u5bf9\u4e00\u6761\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u52a0\u9501\uff0c\u8fd4\u56de\u7ed9 MySQL Server\uff0c\u505a\u4e00\u4e9b DML \u64cd\u4f5c\uff1b\u7136\u540e\u5728\u8bfb\u53d6\u4e0b\u4e00\u6761\u52a0\u9501\uff0c\u76f4\u81f3\u8bfb\u53d6\u5b8c\u6bd5\u3002<\/p><\/blockquote>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"-1\">\u805a\u7c07\u7d22\u5f15<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">InnoDB \u5b58\u50a8\u5f15\u64ce\u7684\u6570\u636e\u7ec4\u7ec7\u65b9\u5f0f\uff0c\u662f\u805a\u7c07\u7d22\u5f15(Cluster Index)\u8868\uff1a\u5b8c\u6574\u7684\u8bb0\u5f55\uff0c\u5b58\u50a8\u5728\u4e3b\u952e\u7d22\u5f15\u4e2d\uff0c\u901a\u8fc7\u4e3b\u952e\u7d22\u5f15\uff0c\u5c31\u53ef\u4ee5\u83b7\u53d6\u8bb0\u5f55\u6240\u6709\u7684\u5217\u3002\u5173\u4e8e\u805a\u7c07\u7d22\u5f15\u8868\u7684\u7ec4\u7ec7\u65b9\u5f0f\uff0c\u53ef\u4ee5\u53c2\u8003 MySQL \u7684\u5b98\u65b9\u6587\u6863\uff1aClustered and Secondary Indexes\uff08http:\/\/dev.mysql.com\/doc\/refman\/5.0\/en\/innodb-index-types.html\uff09\u3002\u672c\u6587\u5047\u8bbe\u8bfb\u8005\u5bf9\u8fd9\u4e2a\uff0c\u5df2\u7ecf\u6709\u4e86\u4e00\u5b9a\u7684\u8ba4\u8bc6\uff0c\u5c31\u4e0d\u518d\u505a\u5177\u4f53\u7684\u4ecb\u7ecd\u3002\u63a5\u4e0b\u6765\u7684\u90e8\u5206\uff0c\u4e3b\u952e\u7d22\u5f15\/\u805a\u7c07\u7d22\u5f15 \u4e24\u4e2a\u540d\u79f0\uff0c\u4f1a\u6709\u4e00\u4e9b\u6df7\u7528\uff0c\u671b\u8bfb\u8005\u77e5\u6653\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"2pl\">2PL<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f20\u7edf RDBMS \u52a0\u9501\u7684\u4e00\u4e2a\u539f\u5219\uff0c\u5c31\u662f 2PL (\u4e8c\u9636\u6bb5\u9501)\uff1aTwo-Phase Locking\uff08http:\/\/en.wikipedia.org\/wiki\/Two-phase_locking\uff09\u3002\u76f8\u5bf9\u800c\u8a00\uff0c2PL \u6bd4\u8f83\u5bb9\u6613\u7406\u89e3\uff0c\u8bf4\u7684\u662f\u9501\u64cd\u4f5c\u5206\u4e3a\u4e24\u4e2a\u9636\u6bb5\uff1a\u52a0\u9501\u9636\u6bb5\u4e0e\u89e3\u9501\u9636\u6bb5\uff0c\u5e76\u4e14\u4fdd\u8bc1\u52a0\u9501\u9636\u6bb5\u4e0e\u89e3\u9501\u9636\u6bb5\u4e0d\u76f8\u4ea4\u3002\u4e0b\u9762\uff0c\u4ecd\u65e7\u4ee5 MySQL \u4e3a\u4f8b\uff0c\u6765\u7b80\u5355\u770b\u770b 2PL \u5728 MySQL \u4e2d\u7684\u5b9e\u73b0\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117141074.jpg\" alt=\"2PL\u52a0\u9501\u8fc7\u7a0b\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ece\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fa\uff0c2PL \u5c31\u662f\u5c06\u52a0\u9501\/\u89e3\u9501\u5206\u4e3a\u4e24\u4e2a\u5b8c\u5168\u4e0d\u76f8\u4ea4\u7684\u9636\u6bb5\u3002\u52a0\u9501\u9636\u6bb5\uff1a\u53ea\u52a0\u9501\uff0c\u4e0d\u653e\u9501\u3002\u89e3\u9501\u9636\u6bb5\uff1a\u53ea\u653e\u9501\uff0c\u4e0d\u52a0\u9501\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"isolationlevel\">\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b Isolation Level<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u9694\u79bb\u7ea7\u522b\uff1aIsolation Level\uff08http:\/\/en.wikipedia.org\/wiki\/Isolation<em>%28database<\/em>systems%29\uff09\uff0c\u4e5f\u662f RDBMS \u7684\u4e00\u4e2a\u5173\u952e\u7279\u6027\u3002\u76f8\u4fe1\u5bf9\u6570\u636e\u5e93\u6709\u6240\u4e86\u89e3\u7684\u670b\u53cb\uff0c\u5bf9\u4e8e 4 \u79cd\u9694\u79bb\u7ea7\u522b\uff1aRead Uncommited\uff0cRead Committed\uff0cRepeatable Read\uff0cSerializable\uff0c\u90fd\u6709\u4e86\u6df1\u5165\u7684\u8ba4\u8bc6\u3002\u672c\u6587\u4e0d\u6253\u7b97\u8ba8\u8bba\u6570\u636e\u5e93\u7406\u8bba\u4e2d\uff0c\u662f\u5982\u4f55\u5b9a\u4e49\u8fd9 4 \u79cd\u9694\u79bb\u7ea7\u522b\u7684\u542b\u4e49\u7684\uff0c\u800c\u662f\u8ddf\u5927\u5bb6\u4ecb\u7ecd\u4e00\u4e0b MySQL\/InnoDB \u662f\u5982\u4f55\u5b9a\u4e49\u8fd9 4 \u79cd\u9694\u79bb\u7ea7\u522b\u7684\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">MySQL\/InnoDB \u5b9a\u4e49\u7684 4 \u79cd\u9694\u79bb\u7ea7\u522b\uff1a\uff08mysql \u7684\u7ea7\u522b\u4e0d\u662f iso\u5b9a\u4e49\u7684\u7ea7\u522b\uff0ciso \u5b9a\u4e49\u7684 RR \u5b58\u5728\u5e7b\u8bfb\uff09<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Read Uncommited\uff1a\u53ef\u4ee5\u8bfb\u53d6\u672a\u63d0\u4ea4\u8bb0\u5f55\u3002\u6b64\u9694\u79bb\u7ea7\u522b\uff0c\u4e0d\u4f1a\u4f7f\u7528\uff0c\u5ffd\u7565\u3002<\/li><li>Read Committed (RC)\uff1a\u5feb\u7167\u8bfb\u5ffd\u7565\uff0c\u672c\u6587\u4e0d\u8003\u8651\u3002\u9488\u5bf9\u5f53\u524d\u8bfb\uff0cRC \u9694\u79bb\u7ea7\u522b\u4fdd\u8bc1\u5bf9\u8bfb\u53d6\u5230\u7684\u8bb0\u5f55\u52a0\u9501 (\u8bb0\u5f55\u9501)\uff0c\u5b58\u5728\u5e7b\u8bfb\u73b0\u8c61\u3002<\/li><li>Repeatable Read (RR)\uff1a\u5feb\u7167\u8bfb\u5ffd\u7565\uff0c\u672c\u6587\u4e0d\u8003\u8651\u3002\u9488\u5bf9\u5f53\u524d\u8bfb\uff0cRR \u9694\u79bb\u7ea7\u522b\u4fdd\u8bc1\u5bf9\u8bfb\u53d6\u5230\u7684\u8bb0\u5f55\u52a0\u9501 (\u8bb0\u5f55\u9501)\uff0c\u540c\u65f6\u4fdd\u8bc1\u5bf9\u8bfb\u53d6\u7684\u8303\u56f4\u52a0\u9501\uff0c\u65b0\u7684\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\u4e0d\u80fd\u591f\u63d2\u5165 (\u95f4\u9699\u9501)\uff0c\u4e0d\u5b58\u5728\u5e7b\u8bfb\u73b0\u8c61\u3002<\/li><li>Serializable\uff1a\u4ece MVCC \u5e76\u53d1\u63a7\u5236\u9000\u5316\u4e3a\u57fa\u4e8e\u9501\u7684\u5e76\u53d1\u63a7\u5236\u3002\u4e0d\u533a\u522b\u5feb\u7167\u8bfb\u4e0e\u5f53\u524d\u8bfb\uff0c\u6240\u6709\u7684\u8bfb\u64cd\u4f5c\u5747\u4e3a\u5f53\u524d\u8bfb\uff0c\u8bfb\u52a0\u8bfb\u9501 (S \u9501)\uff0c\u5199\u52a0\u5199\u9501 (X \u9501)\u3002 Serializable \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u8bfb\u5199\u51b2\u7a81\uff0c\u56e0\u6b64\u5e76\u53d1\u5ea6\u6025\u5267\u4e0b\u964d\uff0c\u5728 MySQL\/InnoDB \u4e0b\u4e0d\u5efa\u8bae\u4f7f\u7528\u3002<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 MYSQL \u7684\u4e8b\u52a1\u5f15\u64ce\u4e2d\uff0cINNODB \u662f\u4f7f\u7528\u8303\u56f4\u6700\u5e7f\u7684\u3002\u5b83\u9ed8\u8ba4\u7684\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u662f REPEATABLE READ(\u53ef\u91cd\u590d\u8bfb\uff09\uff0c\u5728\u6807\u51c6\u7684\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u5b9a\u4e49\u4e0b\uff0cREPEATABLE READ \u662f\u4e0d\u80fd\u9632\u6b62\u5e7b\u8bfb\u4ea7\u751f\u7684\u3002INNODB \u4f7f\u7528\u4e86 next-key locks \u5b9e\u73b0\u4e86\u9632\u6b62\u5e7b\u8bfb\u7684\u53d1\u751f\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"-2\">\u52a0\u9501\u8fc7\u7a0b\u5206\u6790<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"sql\">\u4e00\u6761\u7b80\u5355 SQL \u7684\u52a0\u9501\u5b9e\u73b0\u5206\u6790<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4ecb\u7ecd\u5b8c\u4e00\u4e9b\u80cc\u666f\u77e5\u8bc6\u4e4b\u540e\uff0c\u672c\u6587\u63a5\u4e0b\u6765\u5c06\u9009\u62e9\u51e0\u4e2a\u6709\u4ee3\u8868\u6027\u7684\u4f8b\u5b50\uff0c\u6765\u8be6\u7ec6\u5206\u6790 MySQL \u7684\u52a0\u9501\u5904\u7406\u3002\u5f53\u7136\uff0c\u8fd8\u662f\u4ece\u6700\u7b80\u5355\u7684\u4f8b\u5b50\u8bf4\u8d77\u3002\u7ecf\u5e38\u6709\u670b\u53cb\u53d1\u7ed9\u6211\u4e00\u4e2a SQL\uff0c\u7136\u540e\u95ee\u6211\uff0c\u8fd9\u4e2a SQL \u52a0\u4ec0\u4e48\u9501\uff1f\u5c31\u5982\u540c\u4e0b\u9762\u4e24\u6761\u7b80\u5355\u7684 SQL\uff0c\u4ed6\u4eec\u52a0\u4ec0\u4e48\u9501\uff1f<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\"><code>-- SQL1\uff1a<\/code><code>select * from t1 where id = 10;<\/code><code>-- SQL2\uff1a<\/code><code>delete from t1 where id = 10;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u9488\u5bf9\u8fd9\u4e2a\u95ee\u9898\uff0c\u8be5\u600e\u4e48\u56de\u7b54\uff1f\u6211\u80fd\u60f3\u8c61\u5230\u7684\u4e00\u4e2a\u7b54\u6848\u662f\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SQL1\uff1a\u4e0d\u52a0\u9501\u3002\u56e0\u4e3a MySQL \u662f\u4f7f\u7528\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\u7684\uff0c\u8bfb\u4e0d\u52a0\u9501\u3002\nSQL2\uff1a\u5bf9 id = 10 \u7684\u8bb0\u5f55\u52a0\u5199\u9501 (\u8d70\u4e3b\u952e\u7d22\u5f15)\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u7b54\u6848\u5bf9\u5417\uff1f\u8bf4\u4e0d\u4e0a\u6765\u3002\u5373\u53ef\u80fd\u662f\u6b63\u786e\u7684\uff0c\u4e5f\u6709\u53ef\u80fd\u662f\u9519\u8bef\u7684\uff0c\u5df2\u77e5\u6761\u4ef6\u4e0d\u8db3\uff0c\u8fd9\u4e2a\u95ee\u9898\u6ca1\u6709\u7b54\u6848\u3002\u5982\u679c\u8ba9\u6211\u6765\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\uff0c\u6211\u5fc5\u987b\u8fd8\u8981\u77e5\u9053\u4ee5\u4e0b\u7684\u4e00\u4e9b\u524d\u63d0\uff0c\u524d\u63d0\u4e0d\u540c\uff0c\u6211\u80fd\u7ed9\u51fa\u7684\u7b54\u6848\u4e5f\u5c31\u4e0d\u540c\u3002\u8981\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\uff0c\u8fd8\u7f3a\u5c11\u54ea\u4e9b\u524d\u63d0\u6761\u4ef6\uff1f<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u524d\u63d0\u4e00\uff1aid \u5217\u662f\u4e0d\u662f\u4e3b\u952e\uff1f<\/li><li>\u524d\u63d0\u4e8c\uff1a\u5f53\u524d\u7cfb\u7edf\u7684\u9694\u79bb\u7ea7\u522b\u662f\u4ec0\u4e48\uff1f<\/li><li>\u524d\u63d0\u4e09\uff1aid \u5217\u5982\u679c\u4e0d\u662f\u4e3b\u952e\uff0c\u90a3\u4e48 id \u5217\u4e0a\u6709\u7d22\u5f15\u5417\uff1f<\/li><li>\u524d\u63d0\u56db\uff1aid \u5217\u4e0a\u5982\u679c\u6709\u4e8c\u7ea7\u7d22\u5f15\uff0c\u90a3\u4e48\u8fd9\u4e2a\u7d22\u5f15\u662f\u552f\u4e00\u7d22\u5f15\u5417\uff1f<\/li><li>\u524d\u63d0\u4e94\uff1a\u4e24\u4e2a SQL \u7684\u6267\u884c\u8ba1\u5212\u662f\u4ec0\u4e48\uff1f\u7d22\u5f15\u626b\u63cf\uff1f\u5168\u8868\u626b\u63cf\uff1f<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ca1\u6709\u8fd9\u4e9b\u524d\u63d0\uff0c\u76f4\u63a5\u5c31\u7ed9\u5b9a\u4e00\u6761 SQL\uff0c\u7136\u540e\u95ee\u8fd9\u4e2a SQL \u4f1a\u52a0\u4ec0\u4e48\u9501\uff0c\u90fd\u662f\u5f88\u4e1a\u4f59\u7684\u8868\u73b0\u3002\u800c\u5f53\u8fd9\u4e9b\u95ee\u9898\u6709\u4e86\u660e\u786e\u7684\u7b54\u6848\u4e4b\u540e\uff0c\u7ed9\u5b9a\u7684 SQL \u4f1a\u52a0\u4ec0\u4e48\u9501\uff0c\u4e5f\u5c31\u4e00\u76ee\u4e86\u7136\u3002\u4e0b\u9762\uff0c\u6211\u5c06\u8fd9\u4e9b\u95ee\u9898\u7684\u7b54\u6848\u8fdb\u884c\u7ec4\u5408\uff0c\u7136\u540e\u6309\u7167\u4ece\u6613\u5230\u96be\u7684\u987a\u5e8f\uff0c\u9010\u4e2a\u5206\u6790\u6bcf\u79cd\u7ec4\u5408\u4e0b\uff0c\u5bf9\u5e94\u7684 SQL \u4f1a\u52a0\u54ea\u4e9b\u9501\uff1f<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>\u6ce8\uff1a\u4e0b\u9762\u7684\u8fd9\u4e9b\u7ec4\u5408\uff0c\u6211\u505a\u4e86\u4e00\u4e2a\u524d\u63d0\u5047\u8bbe\uff0c\u4e5f\u5c31\u662f\u6709\u7d22\u5f15\u65f6\uff0c\u6267\u884c\u8ba1\u5212\u4e00\u5b9a\u4f1a\u9009\u62e9\u4f7f\u7528\u7d22\u5f15\u8fdb\u884c\u8fc7\u6ee4 (\u7d22\u5f15\u626b\u63cf)\u3002\u4f46\u5b9e\u9645\u60c5\u51b5\u4f1a\u590d\u6742\u5f88\u591a\uff0c\u771f\u6b63\u7684\u6267\u884c\u8ba1\u5212\uff0c\u8fd8\u662f\u9700\u8981\u6839\u636e MySQL \u8f93\u51fa\u7684\u4e3a\u51c6\u3002<\/p><\/blockquote>\n\n\n\n<ul class=\"wp-block-list\"><li>\u7ec4\u5408\u4e00\uff1aid \u5217\u662f\u4e3b\u952e\uff0cRC \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u4e8c\uff1aid \u5217\u662f\u4e8c\u7ea7\u552f\u4e00\u7d22\u5f15\uff0cRC \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u4e09\uff1aid \u5217\u662f\u4e8c\u7ea7\u975e\u552f\u4e00\u7d22\u5f15\uff0cRC \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u56db\uff1aid \u5217\u4e0a\u6ca1\u6709\u7d22\u5f15\uff0cRC \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u4e94\uff1aid \u5217\u662f\u4e3b\u952e\uff0cRR \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u516d\uff1aid \u5217\u662f\u4e8c\u7ea7\u552f\u4e00\u7d22\u5f15\uff0cRR \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u4e03\uff1aid \u5217\u662f\u4e8c\u7ea7\u975e\u552f\u4e00\u7d22\u5f15\uff0cRR \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u516b\uff1aid \u5217\u4e0a\u6ca1\u6709\u7d22\u5f15\uff0cRR \u9694\u79bb\u7ea7\u522b<\/li><li>\u7ec4\u5408\u4e5d\uff1aSerializable \u9694\u79bb\u7ea7\u522b<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u6392\u5217\u7ec4\u5408\u8fd8\u6ca1\u6709\u5217\u4e3e\u5b8c\u5168\uff0c\u4f46\u662f\u770b\u8d77\u6765\uff0c\u5df2\u7ecf\u5f88\u591a\u4e86\u3002\u771f\u7684\u6709\u5fc5\u8981\u8fd9\u4e48\u590d\u6742\u5417\uff1f\u4e8b\u5b9e\u4e0a\uff0c\u8981\u5206\u6790\u52a0\u9501\uff0c\u5c31\u662f\u9700\u8981\u8fd9\u4e48\u590d\u6742\u3002\u4f46\u662f\u4ece\u53e6\u4e00\u4e2a\u89d2\u5ea6\u6765\u8bf4\uff0c\u53ea\u8981\u4f60\u9009\u5b9a\u4e86\u4e00\u79cd\u7ec4\u5408\uff0cSQL \u9700\u8981\u52a0\u54ea\u4e9b\u9501\uff0c\u5176\u5b9e\u4e5f\u5c31\u786e\u5b9a\u4e86\u3002\u63a5\u4e0b\u6765\uff0c\u5c31\u8ba9\u6211\u4eec\u6765\u9010\u4e2a\u5206\u6790\u8fd9 9 \u79cd\u7ec4\u5408\u4e0b\u7684 SQL \u52a0\u9501\u7b56\u7565\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>\u6ce8\uff1a\u5728\u524d\u9762\u516b\u79cd\u7ec4\u5408\u4e0b\uff0c\u4e5f\u5c31\u662f RC\uff0cRR \u9694\u79bb\u7ea7\u522b\u4e0b\uff0cSQL1\uff1aselect \u64cd\u4f5c\u5747\u4e0d\u52a0\u9501\uff0c\u91c7\u7528\u7684\u662f\u5feb\u7167\u8bfb\uff0c\u56e0\u6b64\u5728\u4e0b\u9762\u7684\u8ba8\u8bba\u4e2d\u5c31\u5ffd\u7565\u4e86\uff0c\u4e3b\u8981\u8ba8\u8bba SQL2\uff1adelete \u64cd\u4f5c\u7684\u52a0\u9501\u3002<\/p><\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrc\">\u7ec4\u5408\u4e00\uff1aid \u4e3b\u952e + RC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u7ec4\u5408\uff0c\u662f\u6700\u7b80\u5355\uff0c\u6700\u5bb9\u6613\u5206\u6790\u7684\u7ec4\u5408\u3002id \u662f\u4e3b\u952e\uff0cRead Committed \u9694\u79bb\u7ea7\u522b\uff0c\u7ed9\u5b9a SQL\uff1adelete from t1 where id = 10; \u53ea\u9700\u8981\u5c06\u4e3b\u952e\u4e0a\uff0cid = 10 \u7684\u8bb0\u5f55\u52a0\u4e0a X \u9501\u5373\u53ef\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117159215.jpg\" alt=\"Read Committed \u9694\u79bb\u7ea7\u522b\u4e3b\u952e\u52a0 X \u9501\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1aid \u662f\u4e3b\u952e\u65f6\uff0c\u6b64 SQL \u53ea\u9700\u8981\u5728 id=10 \u8fd9\u6761\u8bb0\u5f55\u4e0a\u52a0 X \u9501\u5373\u53ef\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrc-1\">\u7ec4\u5408\u4e8c\uff1aid \u552f\u4e00\u7d22\u5f15 + RC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u7ec4\u5408\uff0cid \u4e0d\u662f\u4e3b\u952e\uff0c\u800c\u662f\u4e00\u4e2a Unique \u7684\u4e8c\u7ea7\u7d22\u5f15\u952e\u503c\u3002\u90a3\u4e48\u5728 RC \u9694\u79bb\u7ea7\u522b\u4e0b\uff0cdelete from t1 where id = 10; \u9700\u8981\u52a0\u4ec0\u4e48\u9501\u5462\uff1f\u89c1\u4e0b\u56fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117169517.jpg\" alt=\"Read Committed \u9694\u79bb\u7ea7\u522b\u4e3b\u952e\u52a0 X \u9501\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u6b64\u7ec4\u5408\u4e2d\uff0cid \u662f unique \u7d22\u5f15\uff0c\u800c\u4e3b\u952e\u662f name \u5217\u3002\u6b64\u65f6\uff0c\u52a0\u9501\u7684\u60c5\u51b5\u7531\u4e8e\u7ec4\u5408\u4e00\u6709\u6240\u4e0d\u540c\u3002\u7531\u4e8e id \u662f unique \u7d22\u5f15\uff0c\u56e0\u6b64 delete \u8bed\u53e5\u4f1a\u9009\u62e9\u8d70 id \u5217\u7684\u7d22\u5f15\u8fdb\u884c where \u6761\u4ef6\u7684\u8fc7\u6ee4\uff0c\u5728\u627e\u5230 id=10 \u7684\u8bb0\u5f55\u540e\uff0c\u9996\u5148\u4f1a\u5c06 unique \u7d22\u5f15\u4e0a\u7684 id=10 \u7d22\u5f15\u8bb0\u5f55\u52a0\u4e0aX\u9501\uff0c\u540c\u65f6\uff0c\u4f1a\u6839\u636e\u8bfb\u53d6\u5230\u7684 name \u5217\uff0c\u56de\u4e3b\u952e\u7d22\u5f15(\u805a\u7c07\u7d22\u5f15)\uff0c\u7136\u540e\u5c06\u805a\u7c07\u7d22\u5f15\u4e0a\u7684 name = \u2018d\u2019 \u5bf9\u5e94\u7684\u4e3b\u952e\u7d22\u5f15\u9879\u52a0 X \u9501\u3002\u4e3a\u4ec0\u4e48\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55\u4e5f\u8981\u52a0\u9501\uff1f\u8bd5\u60f3\u4e00\u4e0b\uff0c\u5982\u679c\u5e76\u53d1\u7684\u4e00\u4e2a SQL\uff0c\u662f\u901a\u8fc7\u4e3b\u952e\u7d22\u5f15\u6765\u66f4\u65b0\uff1aupdate t1 set id = 100 where name = \u2018d\u2019; \u6b64\u65f6\uff0c\u5982\u679c delete \u8bed\u53e5\u6ca1\u6709\u5c06\u4e3b\u952e\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55\u52a0\u9501\uff0c\u90a3\u4e48\u5e76\u53d1\u7684 update \u5c31\u4f1a\u611f\u77e5\u4e0d\u5230 delete \u8bed\u53e5\u7684\u5b58\u5728\uff0c\u8fdd\u80cc\u4e86\u540c\u4e00\u8bb0\u5f55\u4e0a\u7684\u66f4\u65b0\/\u5220\u9664\u9700\u8981\u4e32\u884c\u6267\u884c\u7684\u7ea6\u675f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u82e5 id \u5217\u662f unique \u5217\uff0c\u5176\u4e0a\u6709 unique \u7d22\u5f15\u3002\u90a3\u4e48 SQL \u9700\u8981\u52a0\u4e24\u4e2a X \u9501\uff0c\u4e00\u4e2a\u5bf9\u5e94\u4e8e id unique \u7d22\u5f15\u4e0a\u7684 id = 10 \u7684\u8bb0\u5f55\uff0c\u53e6\u4e00\u628a\u9501\u5bf9\u5e94\u4e8e\u805a\u7c07\u7d22\u5f15\u4e0a\u7684[name=&#8217;d&#8217;,id=10]\u7684\u8bb0\u5f55\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrc-2\">\u7ec4\u5408\u4e09\uff1aid \u975e\u552f\u4e00\u7d22\u5f15 + RC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u76f8\u5bf9\u4e8e\u7ec4\u5408\u4e00\u3001\u4e8c\uff0c\u7ec4\u5408\u4e09\u53c8\u53d1\u751f\u4e86\u53d8\u5316\uff0c\u9694\u79bb\u7ea7\u522b\u4ecd\u65e7\u662f RC \u4e0d\u53d8\uff0c\u4f46\u662f id \u5217\u4e0a\u7684\u7ea6\u675f\u53c8\u964d\u4f4e\u4e86\uff0cid \u5217\u4e0d\u518d\u552f\u4e00\uff0c\u53ea\u6709\u4e00\u4e2a\u666e\u901a\u7684\u7d22\u5f15\u3002\u5047\u8bbe delete from t1 where id = 10; \u8bed\u53e5\uff0c\u4ecd\u65e7\u9009\u62e9 id \u5217\u4e0a\u7684\u7d22\u5f15\u8fdb\u884c\u8fc7\u6ee4 where \u6761\u4ef6\uff0c\u90a3\u4e48\u6b64\u65f6\u4f1a\u6301\u6709\u54ea\u4e9b\u9501\uff1f\u540c\u6837\u89c1\u4e0b\u56fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117178442.jpg\" alt=\"id \u975e\u552f\u4e00\u7d22\u5f15 + RC\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u6839\u636e\u6b64\u56fe\uff0c\u53ef\u4ee5\u770b\u5230\uff0c\u9996\u5148\uff0cid \u5217\u7d22\u5f15\u4e0a\uff0c\u6ee1\u8db3 id = 10 \u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\uff0c\u5747\u5df2\u52a0\u9501\u3002\u540c\u65f6\uff0c\u8fd9\u4e9b\u8bb0\u5f55\u5bf9\u5e94\u7684\u4e3b\u952e\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55\u4e5f\u90fd\u52a0\u4e0a\u4e86\u9501\u3002\u4e0e\u7ec4\u5408\u4e8c\u552f\u4e00\u7684\u533a\u522b\u5728\u4e8e\uff0c\u7ec4\u5408\u4e8c\u6700\u591a\u53ea\u6709\u4e00\u4e2a\u6ee1\u8db3\u7b49\u503c\u67e5\u8be2\u7684\u8bb0\u5f55\uff0c\u800c\u7ec4\u5408\u4e09\u4f1a\u5c06\u6240\u6709\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\u90fd\u52a0\u9501\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u82e5 id \u5217\u4e0a\u6709\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u90a3\u4e48\u5bf9\u5e94\u7684\u6240\u6709\u6ee1\u8db3 SQL \u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\uff0c\u90fd\u4f1a\u88ab\u52a0\u9501\u3002\u540c\u65f6\uff0c\u8fd9\u4e9b\u8bb0\u5f55\u5728\u4e3b\u952e\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55\uff0c\u4e5f\u4f1a\u88ab\u52a0\u9501\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrc-3\">\u7ec4\u5408\u56db\uff1aid \u65e0\u7d22\u5f15 + RC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u76f8\u5bf9\u4e8e\u524d\u9762\u4e09\u4e2a\u7ec4\u5408\uff0c\u8fd9\u662f\u4e00\u4e2a\u6bd4\u8f83\u7279\u6b8a\u7684\u60c5\u51b5\u3002id \u5217\u4e0a\u6ca1\u6709\u7d22\u5f15\uff0cwhere id = 10;\u8fd9\u4e2a\u8fc7\u6ee4\u6761\u4ef6\uff0c\u6ca1\u6cd5\u901a\u8fc7\u7d22\u5f15\u8fdb\u884c\u8fc7\u6ee4\uff0c\u90a3\u4e48\u53ea\u80fd\u8d70\u5168\u8868\u626b\u63cf\u505a\u8fc7\u6ee4\u3002\u5bf9\u5e94\u4e8e\u8fd9\u4e2a\u7ec4\u5408\uff0cSQL \u4f1a\u52a0\u4ec0\u4e48\u9501\uff1f\u6216\u8005\u662f\u6362\u53e5\u8bdd\u8bf4\uff0c\u5168\u8868\u626b\u63cf\u65f6\uff0c\u4f1a\u52a0\u4ec0\u4e48\u9501\uff1f\u8fd9\u4e2a\u7b54\u6848\u4e5f\u6709\u5f88\u591a\uff1a\u6709\u4eba\u8bf4\u4f1a\u5728\u8868\u4e0a\u52a0X\u9501\uff1b\u6709\u4eba\u8bf4\u4f1a\u5c06\u805a\u7c07\u7d22\u5f15\u4e0a\uff0c\u9009\u62e9\u51fa\u6765\u7684 id = 10;\u7684\u8bb0\u5f55\u52a0\u4e0aX\u9501\u3002\u90a3\u4e48\u5b9e\u9645\u60c5\u51b5\u5462\uff1f\u8bf7\u770b\u4e0b\u56fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117188907.jpg\" alt=\"\u7ec4\u5408\u56db\uff1aid \u65e0\u7d22\u5f15 + RC\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u7531\u4e8e id \u5217\u4e0a\u6ca1\u6709\u7d22\u5f15\uff0c\u56e0\u6b64\u53ea\u80fd\u8d70\u805a\u7c07\u7d22\u5f15\uff0c\u8fdb\u884c\u5168\u90e8\u626b\u63cf\u3002\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u5230\uff0c\u6ee1\u8db3\u5220\u9664\u6761\u4ef6\u7684\u8bb0\u5f55\u6709\u4e24\u6761\uff0c\u4f46\u662f\uff0c\u805a\u7c07\u7d22\u5f15\u4e0a\u6240\u6709\u7684\u8bb0\u5f55\uff0c\u90fd\u88ab\u52a0\u4e0a\u4e86 X \u9501\u3002\u65e0\u8bba\u8bb0\u5f55\u662f\u5426\u6ee1\u8db3\u6761\u4ef6\uff0c\u5168\u90e8\u88ab\u52a0\u4e0a X \u9501\u3002\u65e2\u4e0d\u662f\u52a0\u8868\u9501\uff0c\u4e5f\u4e0d\u662f\u5728\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u4e0a\u52a0\u884c\u9501\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6709\u4eba\u53ef\u80fd\u4f1a\u95ee\uff1f\u4e3a\u4ec0\u4e48\u4e0d\u662f\u53ea\u5728\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u4e0a\u52a0\u9501\u5462\uff1f\u8fd9\u662f\u7531\u4e8e MySQL \u7684\u5b9e\u73b0\u51b3\u5b9a\u7684\u3002\u5982\u679c\u4e00\u4e2a\u6761\u4ef6\u65e0\u6cd5\u901a\u8fc7\u7d22\u5f15\u5feb\u901f\u8fc7\u6ee4\uff0c\u90a3\u4e48\u5b58\u50a8\u5f15\u64ce\u5c42\u9762\u5c31\u4f1a\u5c06\u6240\u6709\u8bb0\u5f55\u52a0\u9501\u540e\u8fd4\u56de\uff0c\u7136\u540e\u7531 MySQL Server \u5c42\u8fdb\u884c\u8fc7\u6ee4\u3002\u56e0\u6b64\u4e5f\u5c31\u628a\u6240\u6709\u7684\u8bb0\u5f55\uff0c\u90fd\u9501\u4e0a\u4e86\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>\u6ce8\uff1a\u5728\u5b9e\u9645\u7684\u5b9e\u73b0\u4e2d\uff0cMySQL \u6709\u4e00\u4e9b\u6539\u8fdb\uff0c\u5728 MySQL Server \u8fc7\u6ee4\u6761\u4ef6\uff0c\u53d1\u73b0\u4e0d\u6ee1\u8db3\u540e\uff0c\u4f1a\u8c03\u7528 unlock_row \u65b9\u6cd5\uff0c\u628a\u4e0d\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u653e\u9501 (\u8fdd\u80cc\u4e86 2PL \u7684\u7ea6\u675f)\u3002\u8fd9\u6837\u505a\uff0c\u4fdd\u8bc1\u4e86\u6700\u540e\u53ea\u4f1a\u6301\u6709\u6ee1\u8db3\u6761\u4ef6\u8bb0\u5f55\u4e0a\u7684\u9501\uff0c\u4f46\u662f\u6bcf\u6761\u8bb0\u5f55\u7684\u52a0\u9501\u64cd\u4f5c\u8fd8\u662f\u4e0d\u80fd\u7701\u7565\u7684\u3002<\/p><\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u82e5 id \u5217\u4e0a\u6ca1\u6709\u7d22\u5f15\uff0cSQL\u4f1a\u8d70\u805a\u7c07\u7d22\u5f15\u7684\u5168\u626b\u63cf\u8fdb\u884c\u8fc7\u6ee4\uff0c\u7531\u4e8e\u8fc7\u6ee4\u662f\u7531MySQL Server\u5c42\u9762\u8fdb\u884c\u7684\u3002\u56e0\u6b64\u6bcf\u6761\u8bb0\u5f55\uff0c\u65e0\u8bba\u662f\u5426\u6ee1\u8db3\u6761\u4ef6\uff0c\u90fd\u4f1a\u88ab\u52a0\u4e0aX\u9501\u3002\u4f46\u662f\uff0c\u4e3a\u4e86\u6548\u7387\u8003\u91cf\uff0cMySQL\u505a\u4e86\u4f18\u5316\uff0c\u5bf9\u4e8e\u4e0d\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\uff0c\u4f1a\u5728\u5224\u65ad\u540e\u653e\u9501\uff0c\u6700\u7ec8\u6301\u6709\u7684\uff0c\u662f\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u4e0a\u7684\u9501\uff0c\u4f46\u662f\u4e0d\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u4e0a\u7684\u52a0\u9501\/\u653e\u9501\u52a8\u4f5c\u4e0d\u4f1a\u7701\u7565\u3002\u540c\u65f6\uff0c\u4f18\u5316\u4e5f\u8fdd\u80cc\u4e862PL\u7684\u7ea6\u675f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrr\">\u7ec4\u5408\u4e94\uff1aid \u4e3b\u952e + RR<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0a\u9762\u7684\u56db\u4e2a\u7ec4\u5408\uff0c\u90fd\u662f\u5728 Read Committed \u9694\u79bb\u7ea7\u522b\u4e0b\u7684\u52a0\u9501\u884c\u4e3a\uff0c\u63a5\u4e0b\u6765\u7684\u56db\u4e2a\u7ec4\u5408\uff0c\u662f\u5728 Repeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b\u7684\u52a0\u9501\u884c\u4e3a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ec4\u5408\u4e94\uff0cid \u5217\u662f\u4e3b\u952e\u5217\uff0cRepeatable Read \u9694\u79bb\u7ea7\u522b\uff0c\u9488\u5bf9 delete from t1 where id = 10; \u8fd9\u6761 SQL\uff0c\u52a0\u9501\u4e0e\u7ec4\u5408\u4e00\uff1a[id \u4e3b\u952e\uff0cRead Committed ]\u4e00\u81f4\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrr-1\">\u7ec4\u5408\u516d\uff1aid \u552f\u4e00\u7d22\u5f15 + RR<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0e\u7ec4\u5408\u4e94\u7c7b\u4f3c\uff0c\u7ec4\u5408\u516d\u7684\u52a0\u9501\uff0c\u4e0e\u7ec4\u5408\u4e8c\uff1a[id\u552f\u4e00\u7d22\u5f15\uff0cRead Committed]\u4e00\u81f4\u3002\u4e24\u4e2a X \u9501\uff0cid \u552f\u4e00\u7d22\u5f15\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u4e0a\u4e00\u4e2a\uff0c\u5bf9\u5e94\u7684\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55\u4e00\u4e2a\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrr-2\">\u7ec4\u5408\u4e03\uff1aid \u975e\u552f\u4e00\u7d22\u5f15 + RR<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd8\u8bb0\u5f97\u524d\u9762\u63d0\u5230\u7684 MySQL \u7684\u56db\u79cd\u9694\u79bb\u7ea7\u522b\u7684\u533a\u522b\u5417\uff1fRC \u9694\u79bb\u7ea7\u522b\u5141\u8bb8\u5e7b\u8bfb\uff0c\u800c RR \u9694\u79bb\u7ea7\u522b\uff0c\u4e0d\u5141\u8bb8\u5b58\u5728\u5e7b\u8bfb\u3002\u4f46\u662f\u5728\u7ec4\u5408\u4e94\u3001\u7ec4\u5408\u516d\u4e2d\uff0c\u52a0\u9501\u884c\u4e3a\u53c8\u662f\u4e0e RC \u4e0b\u7684\u52a0\u9501\u884c\u4e3a\u5b8c\u5168\u4e00\u81f4\u3002\u90a3\u4e48 RR \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u5982\u4f55\u9632\u6b62\u5e7b\u8bfb\u5462\uff1f\u95ee\u9898\u7684\u7b54\u6848\uff0c\u5c31\u5728\u7ec4\u5408\u4e03\u4e2d\u63ed\u6653\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ec4\u5408\u4e03\uff0cRepeatable Read \u9694\u79bb\u7ea7\u522b\uff0cid \u4e0a\u6709\u4e00\u4e2a\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u6267\u884c delete from t1 where id = 10; \u5047\u8bbe\u9009\u62e9id\u5217\u4e0a\u7684\u7d22\u5f15\u8fdb\u884c\u6761\u4ef6\u8fc7\u6ee4\uff0c\u6700\u540e\u7684\u52a0\u9501\u884c\u4e3a\uff0c\u662f\u600e\u4e48\u6837\u7684\u5462\uff1f\u540c\u6837\u770b\u4e0b\u9762\u8fd9\u5e45\u56fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117199783.jpg\" alt=\"\u7ec4\u5408\u4e03\uff1aid \u975e\u552f\u4e00\u7d22\u5f15 + RR\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u6b64\u56fe\uff0c\u76f8\u5bf9\u4e8e\u7ec4\u5408\u4e09\uff1a[id \u5217\u4e0a\u975e\u552f\u4e00\u9501\uff0cRead Committed]\u770b\u4f3c\u76f8\u540c\uff0c\u5176\u5b9e\u5374\u6709\u5f88\u5927\u7684\u533a\u522b\u3002\u6700\u5927\u7684\u533a\u522b\u5728\u4e8e\uff0c\u8fd9\u5e45\u56fe\u4e2d\u591a\u4e86\u4e00\u4e2a GAP \u9501\uff0c\u800c\u4e14 GAP \u9501\u770b\u8d77\u6765\u4e5f\u4e0d\u662f\u52a0\u5728\u8bb0\u5f55\u4e0a\u7684\uff0c\u5012\u50cf\u662f\u52a0\u8f7d\u4e24\u6761\u8bb0\u5f55\u4e4b\u95f4\u7684\u4f4d\u7f6e\uff0cGAP \u9501\u6709\u4f55\u7528\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u5b9e\u8fd9\u4e2a\u591a\u51fa\u6765\u7684 GAP \u9501\uff0c\u5c31\u662f RR \u9694\u79bb\u7ea7\u522b\uff0c\u76f8\u5bf9\u4e8e RC \u9694\u79bb\u7ea7\u522b\uff0c\u4e0d\u4f1a\u51fa\u73b0\u5e7b\u8bfb\u7684\u5173\u952e\u3002\u786e\u5b9e\uff0cGAP \u9501\u9501\u4f4f\u7684\u4f4d\u7f6e\uff0c\u4e5f\u4e0d\u662f\u8bb0\u5f55\u672c\u8eab\uff0c\u800c\u662f\u4e24\u6761\u8bb0\u5f55\u4e4b\u95f4\u7684 GAP\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u4f55\u4fdd\u8bc1\u4e24\u6b21\u5f53\u524d\u8bfb\u8fd4\u56de\u4e00\u81f4\u7684\u8bb0\u5f55\uff0c\u90a3\u5c31\u9700\u8981\u5728\u7b2c\u4e00\u6b21\u5f53\u524d\u8bfb\u4e0e\u7b2c\u4e8c\u6b21\u5f53\u524d\u8bfb\u4e4b\u95f4\uff0c\u5176\u4ed6\u7684\u4e8b\u52a1\u4e0d\u4f1a\u63d2\u5165\u65b0\u7684\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u5e76\u63d0\u4ea4\u3002\u4e3a\u4e86\u5b9e\u73b0\u8fd9\u4e2a\u529f\u80fd\uff0cGAP \u9501\u5e94\u8fd0\u800c\u751f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u56fe\u4e2d\u6240\u793a\uff0c\u6709\u54ea\u4e9b\u4f4d\u7f6e\u53ef\u4ee5\u63d2\u5165\u65b0\u7684\u6ee1\u8db3\u6761\u4ef6\u7684\u9879 (id = 10)\uff0c\u8003\u8651\u5230B+\u6811\u7d22\u5f15\u7684\u6709\u5e8f\u6027\uff0c\u6ee1\u8db3\u6761\u4ef6\u7684\u9879\u4e00\u5b9a\u662f\u8fde\u7eed\u5b58\u653e\u7684\u3002\u8bb0\u5f55[6,c]\u4e4b\u524d\uff0c\u4e0d\u4f1a\u63d2\u5165 id=10 \u7684\u8bb0\u5f55\uff1b[6,c]\u4e0e[10,b]\u95f4\u53ef\u4ee5\u63d2\u5165[10, aa]\uff1b[10,b]\u4e0e[10,d]\u95f4\uff0c\u53ef\u4ee5\u63d2\u5165\u65b0\u7684[10,bb],[10,c]\u7b49\uff1b[10,d]\u4e0e[11,f]\u95f4\u53ef\u4ee5\u63d2\u5165\u6ee1\u8db3\u6761\u4ef6\u7684[10,e],[10,z]\u7b49\uff1b\u800c[11,f]\u4e4b\u540e\u4e5f\u4e0d\u4f1a\u63d2\u5165\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u3002\u56e0\u6b64\uff0c\u4e3a\u4e86\u4fdd\u8bc1[6,c]\u4e0e[10,b]\u95f4\uff0c[10,b]\u4e0e[10,d]\u95f4\uff0c[10,d]\u4e0e[11,f]\u4e0d\u4f1a\u63d2\u5165\u65b0\u7684\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\uff0cMySQL \u9009\u62e9\u4e86\u7528 GAP \u9501\uff0c\u5c06\u8fd9\u4e09\u4e2a GAP \u7ed9\u9501\u8d77\u6765\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Insert \u64cd\u4f5c\uff0c\u5982 insert [10,aa]\uff0c\u9996\u5148\u4f1a\u5b9a\u4f4d\u5230[6,c]\u4e0e[10,b]\u95f4\uff0c\u7136\u540e\u5728\u63d2\u5165\u524d\uff0c\u4f1a\u68c0\u67e5\u8fd9\u4e2a GAP \u662f\u5426\u5df2\u7ecf\u88ab\u9501\u4e0a\uff0c\u5982\u679c\u88ab\u9501\u4e0a\uff0c\u5219 Insert \u4e0d\u80fd\u63d2\u5165\u8bb0\u5f55\u3002\u56e0\u6b64\uff0c\u901a\u8fc7\u7b2c\u4e00\u904d\u7684\u5f53\u524d\u8bfb\uff0c\u4e0d\u4ec5\u5c06\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u9501\u4e0a (X\u9501)\uff0c\u4e0e\u7ec4\u5408\u4e09\u7c7b\u4f3c\u3002\u540c\u65f6\u8fd8\u662f\u589e\u52a0 3 \u628a GAP \u9501\uff0c\u5c06\u53ef\u80fd\u63d2\u5165\u6ee1\u8db3\u6761\u4ef6\u8bb0\u5f55\u7684 3 \u4e2a GAP \u7ed9\u9501\u4e0a\uff0c\u4fdd\u8bc1\u540e\u7eed\u7684 Insert \u4e0d\u80fd\u63d2\u5165\u65b0\u7684 id=10 \u7684\u8bb0\u5f55\uff0c\u4e5f\u5c31\u675c\u7edd\u4e86\u540c\u4e00\u4e8b\u52a1\u7684\u7b2c\u4e8c\u6b21\u5f53\u524d\u8bfb\uff0c\u51fa\u73b0\u5e7b\u8c61\u7684\u60c5\u51b5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6709\u5fc3\u7684\u670b\u53cb\u770b\u5230\u8fd9\u513f\uff0c\u53ef\u4ee5\u4f1a\u95ee\uff1a\u65e2\u7136\u9632\u6b62\u5e7b\u8bfb\uff0c\u9700\u8981\u9760 GAP \u9501\u7684\u4fdd\u62a4\uff0c\u4e3a\u4ec0\u4e48\u7ec4\u5408\u4e94\u3001\u7ec4\u5408\u516d\uff0c\u4e5f\u662f RR \u9694\u79bb\u7ea7\u522b\uff0c\u5374\u4e0d\u9700\u8981\u52a0 GAP \u9501\u5462\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9996\u5148\uff0c\u8fd9\u662f\u4e00\u4e2a\u597d\u95ee\u9898\u3002\u5176\u6b21\uff0c\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\uff0c\u4e5f\u5f88\u7b80\u5355\u3002GAP \u9501\u7684\u76ee\u7684\uff0c\u662f\u4e3a\u4e86\u9632\u6b62\u540c\u4e00\u4e8b\u52a1\u7684\u4e24\u6b21\u5f53\u524d\u8bfb\uff0c\u51fa\u73b0\u5e7b\u8bfb\u7684\u60c5\u51b5\u3002\u800c\u7ec4\u5408\u4e94\uff0cid \u662f\u4e3b\u952e\uff1b\u7ec4\u5408\u516d\uff0cid \u662f unique \u952e\uff0c\u90fd\u80fd\u591f\u4fdd\u8bc1\u552f\u4e00\u6027\u3002\u4e00\u4e2a\u7b49\u503c\u67e5\u8be2\uff0c\u6700\u591a\u53ea\u80fd\u8fd4\u56de\u4e00\u6761\u8bb0\u5f55\uff0c\u800c\u4e14\u65b0\u7684\u76f8\u540c\u53d6\u503c\u7684\u8bb0\u5f55\uff0c\u4e00\u5b9a\u4e0d\u4f1a\u5728\u65b0\u63d2\u5165\u8fdb\u6765\uff0c\u56e0\u6b64\u4e5f\u5c31\u907f\u514d\u4e86 GAP \u9501\u7684\u4f7f\u7528\u3002\u5176\u5b9e\uff0c\u9488\u5bf9\u6b64\u95ee\u9898\uff0c\u8fd8\u6709\u4e00\u4e2a\u66f4\u6df1\u5165\u7684\u95ee\u9898\uff1a\u5982\u679c\u7ec4\u5408\u4e94\u3001\u7ec4\u5408\u516d\u4e0b\uff0c\u9488\u5bf9 SQL\uff1aselect * from t1 where id = 10 for update; \u7b2c\u4e00\u6b21\u67e5\u8be2\uff0c\u6ca1\u6709\u627e\u5230\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\uff0c\u90a3\u4e48 GAP \u9501\u662f\u5426\u8fd8\u80fd\u591f\u7701\u7565\uff1f\u6b64\u95ee\u9898\u7559\u7ed9\u5927\u5bb6\u601d\u8003\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1aRepeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b\uff0cid \u5217\u4e0a\u6709\u4e00\u4e2a\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u5bf9\u5e94 SQL\uff1adelete from t1 where id = 10; \u9996\u5148\uff0c\u901a\u8fc7 id \u7d22\u5f15\u5b9a\u4f4d\u5230\u7b2c\u4e00\u6761\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\uff0c\u52a0\u8bb0\u5f55\u4e0a\u7684 X \u9501\uff0c\u52a0 GAP \u4e0a\u7684 GAP \u9501\uff0c\u7136\u540e\u52a0\u4e3b\u952e\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55 X \u9501\uff0c\u7136\u540e\u8fd4\u56de\uff1b\u7136\u540e\u8bfb\u53d6\u4e0b\u4e00\u6761\uff0c\u91cd\u590d\u8fdb\u884c\u3002\u76f4\u81f3\u8fdb\u884c\u5230\u7b2c\u4e00\u6761\u4e0d\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55[11,f]\uff0c\u6b64\u65f6\uff0c\u4e0d\u9700\u8981\u52a0\u8bb0\u5f55 X \u9501\uff0c\u4f46\u662f\u4ecd\u65e7\u9700\u8981\u52a0 GAP \u9501\uff0c\u6700\u540e\u8fd4\u56de\u7ed3\u675f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ec0\u4e48\u65f6\u5019\u4f1a\u53d6\u5f97 gap lock \u6216 nextkey lock \u8fd9\u548c\u9694\u79bb\u7ea7\u522b\u6709\u5173\uff0c\u53ea\u5728 REPEATABLE READ \u6216\u4ee5\u4e0a\u7684\u9694\u79bb\u7ea7\u522b\u4e0b\u7684\u7279\u5b9a\u64cd\u4f5c\u624d\u4f1a\u53d6\u5f97 gap lock \u6216 nextkey lock\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"idrr-3\">\u7ec4\u5408\u516b\uff1aid \u65e0\u7d22\u5f15 + RR<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ec4\u5408\u516b\uff0cRepeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b\u7684\u6700\u540e\u4e00\u79cd\u60c5\u51b5\uff0cid \u5217\u4e0a\u6ca1\u6709\u7d22\u5f15\u3002\u6b64\u65f6 SQL\uff1adelete from t1 where id = 10; \u6ca1\u6709\u5176\u4ed6\u7684\u8def\u5f84\u53ef\u4ee5\u9009\u62e9\uff0c\u53ea\u80fd\u8fdb\u884c\u5168\u8868\u626b\u63cf\u3002\u6700\u7ec8\u7684\u52a0\u9501\u60c5\u51b5\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117209920.jpg\" alt=\"\u7ec4\u5408\u516b\uff1aid \u65e0\u7d22\u5f15 + RR\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u56fe\uff0c\u8fd9\u662f\u4e00\u4e2a\u5f88\u6050\u6016\u7684\u73b0\u8c61\u3002\u9996\u5148\uff0c\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u90fd\u88ab\u52a0\u4e0a\u4e86 X \u9501\u3002\u5176\u6b21\uff0c\u805a\u7c07\u7d22\u5f15\u6bcf\u6761\u8bb0\u5f55\u95f4\u7684\u95f4\u9699(GAP)\uff0c\u4e5f\u540c\u65f6\u88ab\u52a0\u4e0a\u4e86 GAP \u9501\u3002\u8fd9\u4e2a\u793a\u4f8b\u8868\uff0c\u53ea\u6709 6 \u6761\u8bb0\u5f55\uff0c\u4e00\u5171\u9700\u8981 6 \u4e2a\u8bb0\u5f55\u9501\uff0c7 \u4e2a GAP \u9501\u3002\u8bd5\u60f3\uff0c\u5982\u679c\u8868\u4e0a\u6709 1000 \u4e07\u6761\u8bb0\u5f55\u5462\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u8fd9\u4e2a\u8868\u4e0a\uff0c\u9664\u4e86\u4e0d\u52a0\u9501\u7684\u5feb\u7167\u5ea6\uff0c\u5176\u4ed6\u4efb\u4f55\u52a0\u9501\u7684\u5e76\u53d1 SQL\uff0c\u5747\u4e0d\u80fd\u6267\u884c\uff0c\u4e0d\u80fd\u66f4\u65b0\uff0c\u4e0d\u80fd\u5220\u9664\uff0c\u4e0d\u80fd\u63d2\u5165\uff0c\u5168\u8868\u88ab\u9501\u6b7b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u7136\uff0c\u8ddf\u7ec4\u5408\u56db\uff1a[id\u65e0\u7d22\u5f15, Read Committed]\u7c7b\u4f3c\uff0c\u8fd9\u4e2a\u60c5\u51b5\u4e0b\uff0cMySQL \u4e5f\u505a\u4e86\u4e00\u4e9b\u4f18\u5316\uff0c\u5c31\u662f\u6240\u8c13\u7684 semi-consistent read\u3002semi-consistent read \u5f00\u542f\u7684\u60c5\u51b5\u4e0b\uff0c\u5bf9\u4e8e\u4e0d\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u8bb0\u5f55\uff0cMySQL \u4f1a\u63d0\u524d\u653e\u9501\u3002\u9488\u5bf9\u4e0a\u9762\u7684\u8fd9\u4e2a\u7528\u4f8b\uff0c\u5c31\u662f\u9664\u4e86\u8bb0\u5f55[d,10]\uff0c[g,10]\u4e4b\u5916\uff0c\u6240\u6709\u7684\u8bb0\u5f55\u9501\u90fd\u4f1a\u88ab\u91ca\u653e\uff0c\u540c\u65f6\u4e0d\u52a0 GAP \u9501\u3002semi-consistent read \u5982\u4f55\u89e6\u53d1\uff1a\u8981\u4e48\u662f read committed \u9694\u79bb\u7ea7\u522b\uff1b\u8981\u4e48\u662f Repeatable Read \u9694\u79bb\u7ea7\u522b\uff0c\u540c\u65f6\u8bbe\u7f6e\u4e86 innodb<em>locks<\/em>unsafe<em>for<\/em>binlog \u53c2\u6570\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u5728 Repeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u5982\u679c\u8fdb\u884c\u5168\u8868\u626b\u63cf\u7684\u5f53\u524d\u8bfb\uff0c\u90a3\u4e48\u4f1a\u9501\u4e0a\u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u540c\u65f6\u4f1a\u9501\u4e0a\u805a\u7c07\u7d22\u5f15\u5185\u7684\u6240\u6709 GAP\uff0c\u675c\u7edd\u6240\u6709\u7684\u5e76\u53d1 \u66f4\u65b0\/\u5220\u9664\/\u63d2\u5165 \u64cd\u4f5c\u3002\u5f53\u7136\uff0c\u4e5f\u53ef\u4ee5\u901a\u8fc7\u89e6\u53d1 semi-consistent read\uff0c\u6765\u7f13\u89e3\u52a0\u9501\u5f00\u9500\u4e0e\u5e76\u53d1\u5f71\u54cd\uff0c\u4f46\u662f semi-consistent read \u672c\u8eab\u4e5f\u4f1a\u5e26\u6765\u5176\u4ed6\u95ee\u9898\uff0c\u4e0d\u5efa\u8bae\u4f7f\u7528\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"serializable\">\u7ec4\u5408\u4e5d\uff1aSerializable<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u9488\u5bf9\u524d\u9762\u63d0\u5230\u7684\u7b80\u5355\u7684 SQL\uff0c\u6700\u540e\u4e00\u4e2a\u60c5\u51b5\uff1aSerializable \u9694\u79bb\u7ea7\u522b\u3002\u5bf9\u4e8e SQL2\uff1adelete from t1 where id = 10; \u6765\u8bf4\uff0cSerializable \u9694\u79bb\u7ea7\u522b\u4e0e Repeatable Read \u9694\u79bb\u7ea7\u522b\u5b8c\u5168\u4e00\u81f4\uff0c\u56e0\u6b64\u4e0d\u505a\u4ecb\u7ecd\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Serializable \u9694\u79bb\u7ea7\u522b\uff0c\u5f71\u54cd\u7684\u662fSQL1\uff1aselect * from t1 where id = 10; \u8fd9\u6761 SQL\uff0c\u5728 RC\uff0cRR \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u90fd\u662f\u5feb\u7167\u8bfb\uff0c\u4e0d\u52a0\u9501\u3002\u4f46\u662f\u5728 Serializable \u9694\u79bb\u7ea7\u522b\uff0cSQL1 \u4f1a\u52a0\u8bfb\u9501\uff0c\u4e5f\u5c31\u662f\u8bf4\u5feb\u7167\u8bfb\u4e0d\u590d\u5b58\u5728\uff0cMVCC \u5e76\u53d1\u63a7\u5236\u964d\u7ea7\u4e3a Lock-Based CC\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u5728 MySQL\/InnoDB \u4e2d\uff0c\u6240\u8c13\u7684\u8bfb\u4e0d\u52a0\u9501\uff0c\u5e76\u4e0d\u9002\u7528\u4e8e\u6240\u6709\u7684\u60c5\u51b5\uff0c\u800c\u662f\u9694\u79bb\u7ea7\u522b\u76f8\u5173\u7684\u3002Serializable \u9694\u79bb\u7ea7\u522b\uff0c\u8bfb\u4e0d\u52a0\u9501\u5c31\u4e0d\u518d\u6210\u7acb\uff0c\u6240\u6709\u7684\u8bfb\u64cd\u4f5c\uff0c\u90fd\u662f\u5f53\u524d\u8bfb\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"sql-1\">\u4e00\u6761\u590d\u6742\u7684 sql \u8bed\u53e5<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5199\u5230\u8fd9\u91cc\uff0c\u5176\u5b9e MySQL \u7684\u52a0\u9501\u5b9e\u73b0\u4e5f\u5df2\u7ecf\u4ecb\u7ecd\u7684\u516b\u516b\u4e5d\u4e5d\u3002\u53ea\u8981\u5c06\u672c\u6587\u4e0a\u9762\u7684\u5206\u6790\u601d\u8def\uff0c\u5927\u90e8\u5206\u7684 SQL\uff0c\u90fd\u80fd\u5206\u6790\u51fa\u5176\u4f1a\u52a0\u54ea\u4e9b\u9501\u3002\u800c\u8fd9\u91cc\uff0c\u518d\u6765\u770b\u4e00\u4e2a\u7a0d\u5fae\u590d\u6742\u70b9\u7684 SQL\uff0c\u7528\u4e8e\u8bf4\u660eMySQL\u52a0\u9501\u7684\u53e6\u5916\u4e00\u4e2a\u903b\u8f91\u3002SQL \u7528\u4f8b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117219875.jpg\" alt=\"Repeatable Read \u9694\u79bb SQL \u52a0\u9501\u60c5\u51b5\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u56fe\u4e2d\u7684 SQL\uff0c\u4f1a\u52a0\u4ec0\u4e48\u9501\uff1f\u5047\u5b9a\u5728 Repeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b (Read Committed \u9694\u79bb\u7ea7\u522b\u4e0b\u7684\u52a0\u9501\u60c5\u51b5\uff0c\u672c\u6587\u4e0d\u5206\u6790)\uff0c\u540c\u65f6\uff0c\u5047\u8bbe SQL \u8d70\u7684\u662f idx<em>t1<\/em>pu \u7d22\u5f15\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8be6\u7ec6\u5206\u6790\u8fd9\u6761 SQL \u7684\u52a0\u9501\u60c5\u51b5\u524d\uff0c\u8fd8\u9700\u8981\u6709\u4e00\u4e2a\u77e5\u8bc6\u50a8\u5907\uff0c\u90a3\u5c31\u662f\u4e00\u4e2a SQL \u4e2d\u7684 where \u6761\u4ef6\u5982\u4f55\u62c6\u5206\uff1f<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Index key\uff1apubtime &gt; 1 and puptime &lt; 20\u3002\u6b64\u6761\u4ef6\uff0c\u7528\u4e8e\u786e\u5b9aSQL\u5728idx<em>t1<\/em>pu\u7d22\u5f15\u4e0a\u7684\u67e5\u8be2\u8303\u56f4\u3002<\/li><li>Index Filter\uff1auserid = \u2018hdc\u2019 \u3002\u6b64\u6761\u4ef6\uff0c\u53ef\u4ee5\u5728idx<em>t1<\/em>pu\u7d22\u5f15\u4e0a\u8fdb\u884c\u8fc7\u6ee4\uff0c\u4f46\u4e0d\u5c5e\u4e8eIndex Key\u3002<\/li><li>Table Filter\uff1acomment is not NULL\u3002\u6b64\u6761\u4ef6\uff0c\u5728idx<em>t1<\/em>pu\u7d22\u5f15\u4e0a\u65e0\u6cd5\u8fc7\u6ee4\uff0c\u53ea\u80fd\u5728\u805a\u7c07\u7d22\u5f15\u4e0a\u8fc7\u6ee4\u3002<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5206\u6790\u51fa SQL where \u6761\u4ef6\u7684\u6784\u6210\u4e4b\u540e\uff0c\u518d\u6765\u770b\u770b\u8fd9\u6761 SQL \u7684\u52a0\u9501\u60c5\u51b5 (RR \u9694\u79bb\u7ea7\u522b)\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117229832.jpg\" alt=\"SQL \u7684\u52a0\u9501\u60c5\u51b5\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u51fa\uff0c\u5728 Repeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u7531 Index Key \u6240\u786e\u5b9a\u7684\u8303\u56f4\uff0c\u88ab\u52a0\u4e0a\u4e86 GAP \u9501\uff1bIndex Filter \u9501\u7ed9\u5b9a\u7684\u6761\u4ef6 (userid = \u2018hdc\u2019)\u4f55\u65f6\u8fc7\u6ee4\uff0c\u89c6 MySQL \u7684\u7248\u672c\u800c\u5b9a\uff0c\u5728 MySQL 5.6 \u7248\u672c\u4e4b\u524d\uff0c\u4e0d\u652f\u6301 Index Condition Pushdown(ICP)\uff0c\u56e0\u6b64 Index Filter \u5728 MySQL Server \u5c42\u8fc7\u6ee4\uff0c\u5728 5.6 \u540e\u652f\u6301\u4e86 Index Condition Pushdown\uff0c\u5219\u5728 index \u4e0a\u8fc7\u6ee4\u3002\u82e5\u4e0d\u652f\u6301 ICP\uff0c\u4e0d\u6ee1\u8db3 Index Filter \u7684\u8bb0\u5f55\uff0c\u4e5f\u9700\u8981\u52a0\u4e0a\u8bb0\u5f55 X \u9501\uff0c\u82e5\u652f\u6301 ICP\uff0c\u5219\u4e0d\u6ee1\u8db3 Index Filter \u7684\u8bb0\u5f55\uff0c\u65e0\u9700\u52a0\u8bb0\u5f55 X \u9501 (\u56fe\u4e2d\uff0c\u7528\u7ea2\u8272\u7bad\u5934\u6807\u51fa\u7684X\u9501\uff0c\u662f\u5426\u8981\u52a0\uff0c\u89c6\u662f\u5426\u652f\u6301 ICP \u800c\u5b9a)\uff1b\u800c Table Filter \u5bf9\u5e94\u7684\u8fc7\u6ee4\u6761\u4ef6\uff0c\u5219\u5728\u805a\u7c07\u7d22\u5f15\u4e2d\u8bfb\u53d6\u540e\uff0c\u5728 MySQL Server \u5c42\u9762\u8fc7\u6ee4\uff0c\u56e0\u6b64\u805a\u7c07\u7d22\u5f15\u4e0a\u4e5f\u9700\u8981X\u9501\u3002\u6700\u540e\uff0c\u9009\u53d6\u51fa\u4e86\u4e00\u6761\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55[8,hdc,d,5,good]\uff0c\u4f46\u662f\u52a0\u9501\u7684\u6570\u91cf\uff0c\u8981\u8fdc\u8fdc\u5927\u4e8e\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u6570\u91cf\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u5728 Repeatable Read \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u9488\u5bf9\u4e00\u4e2a\u590d\u6742\u7684 SQL\uff0c\u9996\u5148\u9700\u8981\u63d0\u53d6\u5176 where \u6761\u4ef6\u3002Index Key \u786e\u5b9a\u7684\u8303\u56f4\uff0c\u9700\u8981\u52a0\u4e0a GAP \u9501\uff1bIndex Filter \u8fc7\u6ee4\u6761\u4ef6\uff0c\u89c6 MySQL \u7248\u672c\u662f\u5426\u652f\u6301 ICP\uff0c\u82e5\u652f\u6301 ICP\uff0c\u5219\u4e0d\u6ee1\u8db3 Index Filter \u7684\u8bb0\u5f55\uff0c\u4e0d\u52a0 X \u9501\uff0c\u5426\u5219\u9700\u8981X\u9501\uff1bTable Filter \u8fc7\u6ee4\u6761\u4ef6\uff0c\u65e0\u8bba\u662f\u5426\u6ee1\u8db3\uff0c\u90fd\u9700\u8981\u52a0 X \u9501\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"-3\">\u6b7b\u9501\u539f\u7406\u4e0e\u5206\u6790<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u6587\u524d\u9762\u7684\u90e8\u5206\uff0c\u57fa\u672c\u4e0a\u5df2\u7ecf\u6db5\u76d6\u4e86 MySQL\/InnoDB \u6240\u6709\u7684\u52a0\u9501\u89c4\u5219\u3002\u6df1\u5165\u7406\u89e3 MySQL \u5982\u4f55\u52a0\u9501\uff0c\u6709\u4e24\u4e2a\u6bd4\u8f83\u91cd\u8981\u7684\u4f5c\u7528\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u53ef\u4ee5\u6839\u636e MySQL \u7684\u52a0\u9501\u89c4\u5219\uff0c\u5199\u51fa\u4e0d\u4f1a\u53d1\u751f\u6b7b\u9501\u7684 SQL\uff1b<\/li><li>\u53ef\u4ee5\u6839\u636e MySQL \u7684\u52a0\u9501\u89c4\u5219\uff0c\u5b9a\u4f4d\u51fa\u7ebf\u4e0a\u4ea7\u751f\u6b7b\u9501\u7684\u539f\u56e0\uff1b<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\uff0c\u6765\u770b\u770b\u4e24\u4e2a\u6b7b\u9501\u7684\u4f8b\u5b50 (\u4e00\u4e2a\u662f\u4e24\u4e2a Session \u7684\u4e24\u6761 SQL \u4ea7\u751f\u6b7b\u9501\uff1b\u53e6\u4e00\u4e2a\u662f\u4e24\u4e2a Session \u7684\u4e00\u6761 SQL\uff0c\u4ea7\u751f\u6b7b\u9501)\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117240108.jpg\" alt=\"SQL \u6b7b\u9501\u539f\u7406\u4e0e\u5206\u6790\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/gitee.com\/xmtblog\/img\/raw\/master\/1585117249988.jpg\" alt=\"SQL \u6b7b\u9501\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0a\u9762\u7684\u4e24\u4e2a\u6b7b\u9501\u7528\u4f8b\u3002\u7b2c\u4e00\u4e2a\u975e\u5e38\u597d\u7406\u89e3\uff0c\u4e5f\u662f\u6700\u5e38\u89c1\u7684\u6b7b\u9501\uff0c\u6bcf\u4e2a\u4e8b\u52a1\u6267\u884c\u4e24\u6761 SQL\uff0c\u5206\u522b\u6301\u6709\u4e86\u4e00\u628a\u9501\uff0c\u7136\u540e\u52a0\u53e6\u4e00\u628a\u9501\uff0c\u4ea7\u751f\u6b7b\u9501\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7b2c\u4e8c\u4e2a\u7528\u4f8b\uff0c\u867d\u7136\u6bcf\u4e2a Session \u90fd\u53ea\u6709\u4e00\u6761\u8bed\u53e5\uff0c\u4ecd\u65e7\u4f1a\u4ea7\u751f\u6b7b\u9501\u3002\u8981\u5206\u6790\u8fd9\u4e2a\u6b7b\u9501\uff0c\u9996\u5148\u5fc5\u987b\u7528\u5230\u672c\u6587\u524d\u9762\u63d0\u5230\u7684 MySQL \u52a0\u9501\u7684\u89c4\u5219\u3002\u9488\u5bf9 Session 1\uff0c\u4ece name \u7d22\u5f15\u51fa\u53d1\uff0c\u8bfb\u5230\u7684[hdc, 1]\uff0c[hdc, 6] \u5747\u6ee1\u8db3\u6761\u4ef6\uff0c\u4e0d\u4ec5\u4f1a\u52a0 name \u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55X\u9501\uff0c\u800c\u4e14\u4f1a\u52a0\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55 X \u9501\uff0c\u52a0\u9501\u987a\u5e8f\u4e3a\u5148[1,hdc,100]\uff0c\u540e[6,hdc,10]\u3002\u800c Session 2\uff0c\u4ece pubtime \u7d22\u5f15\u51fa\u53d1\uff0c[10,6],[100,1]\u5747\u6ee1\u8db3\u8fc7\u6ee4\u6761\u4ef6\uff0c\u540c\u6837\u4e5f\u4f1a\u52a0\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55 X \u9501\uff0c\u52a0\u9501\u987a\u5e8f\u4e3a[6,hdc,10]\uff0c\u540e[1,hdc,100]\u3002\u53d1\u73b0\u6ca1\u6709\uff0c\u8ddf Session 1 \u7684\u52a0\u9501\u987a\u5e8f\u6b63\u597d\u76f8\u53cd\uff0c\u5982\u679c\u4e24\u4e2a Session \u6070\u597d\u90fd\u6301\u6709\u4e86\u7b2c\u4e00\u628a\u9501\uff0c\u8bf7\u6c42\u52a0\u7b2c\u4e8c\u628a\u9501\uff0c\u6b7b\u9501\u5c31\u53d1\u751f\u4e86\u3002\u3000\u3000<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u8bba\uff1a\u6b7b\u9501\u7684\u53d1\u751f\u4e0e\u5426\uff0c\u5e76\u4e0d\u5728\u4e8e\u4e8b\u52a1\u4e2d\u6709\u591a\u5c11\u6761 SQL \u8bed\u53e5\uff0c\u6b7b\u9501\u7684\u5173\u952e\u5728\u4e8e\uff1a\u4e24\u4e2a(\u6216\u4ee5\u4e0a)\u7684 Session \u52a0\u9501\u7684\u987a\u5e8f\u4e0d\u4e00\u81f4\u3002\u800c\u4f7f\u7528\u672c\u6587\u4e0a\u9762\u63d0\u5230\u7684\uff0c\u5206\u6790 MySQL \u6bcf\u6761 SQL \u8bed\u53e5\u7684\u52a0\u9501\u89c4\u5219\uff0c\u5206\u6790\u51fa\u6bcf\u6761\u8bed\u53e5\u7684\u52a0\u9501\u987a\u5e8f\uff0c\u7136\u540e\u68c0\u67e5\u591a\u4e2a\u5e76\u53d1 SQL \u95f4\u662f\u5426\u5b58\u5728\u4ee5\u76f8\u53cd\u7684\u987a\u5e8f\u52a0\u9501\u7684\u60c5\u51b5\uff0c\u5c31\u53ef\u4ee5\u5206\u6790\u51fa\u5404\u79cd\u6f5c\u5728\u7684\u6b7b\u9501\u60c5\u51b5\uff0c\u4e5f\u53ef\u4ee5\u5206\u6790\u51fa\u7ebf\u4e0a\u6b7b\u9501\u53d1\u751f\u7684\u539f\u56e0\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"-4\">\u603b\u7ed3<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u5199\u5230\u8fd9\u513f\uff0c\u672c\u6587\u4e5f\u544a\u4e00\u6bb5\u843d\uff0c\u505a\u4e00\u4e2a\u7b80\u5355\u7684\u603b\u7ed3\uff0c\u8981\u505a\u7684\u5b8c\u5168\u638c\u63e1 MySQL\/InnoDB \u7684\u52a0\u9501\u89c4\u5219\uff0c\u751a\u81f3\u662f\u5176\u4ed6\u4efb\u4f55\u6570\u636e\u5e93\u7684\u52a0\u9501\u89c4\u5219\uff0c\u9700\u8981\u5177\u5907\u4ee5\u4e0b\u7684\u4e00\u4e9b\u77e5\u8bc6\u70b9\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4e86\u89e3\u6570\u636e\u5e93\u7684\u4e00\u4e9b\u57fa\u672c\u7406\u8bba\u77e5\u8bc6\uff1a\u6570\u636e\u7684\u5b58\u50a8\u683c\u5f0f (\u5806\u7ec4\u7ec7\u8868 vs \u805a\u7c07\u7d22\u5f15\u8868)\uff1b\u5e76\u53d1\u63a7\u5236\u534f\u8bae (MVCC vs Lock-Based CC)\uff1bTwo-Phase Locking\uff1b\u6570\u636e\u5e93\u7684\u9694\u79bb\u7ea7\u522b\u5b9a\u4e49 (Isolation Level)\uff1b<\/li><li>\u4e86\u89e3 SQL \u672c\u8eab\u7684\u6267\u884c\u8ba1\u5212 (\u4e3b\u952e\u626b\u63cf vs \u552f\u4e00\u952e\u626b\u63cf vs \u8303\u56f4\u626b\u63cf vs \u5168\u8868\u626b\u63cf)\uff1b<\/li><li>\u4e86\u89e3\u6570\u636e\u5e93\u672c\u8eab\u7684\u4e00\u4e9b\u5b9e\u73b0\u7ec6\u8282 (\u8fc7\u6ee4\u6761\u4ef6\u63d0\u53d6\uff1bIndex Condition Pushdown\uff1bSemi-Consistent Read)\uff1b<\/li><li>\u4e86\u89e3\u6b7b\u9501\u4ea7\u751f\u7684\u539f\u56e0\u53ca\u5206\u6790\u7684\u65b9\u6cd5 (\u52a0\u9501\u987a\u5e8f\u4e0d\u4e00\u81f4\uff1b\u5206\u6790\u6bcf\u4e2a SQL \u7684\u52a0\u9501\u987a\u5e8f)<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u6709\u4e86\u8fd9\u4e9b\u77e5\u8bc6\u70b9\uff0c\u518d\u52a0\u4e0a\u9002\u5f53\u7684\u5b9e\u6218\u7ecf\u9a8c\uff0c\u5168\u9762\u638c\u63a7 MySQL\/InnoDB \u7684\u52a0\u9501\u89c4\u5219\uff0c\u5f53\u4e0d\u5728\u8bdd\u4e0b\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u53c2\u8003\u8d44\u6599<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><a rel=\"noreferrer noopener\" aria-label=\"\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\" href=\"https:\/\/en.wikipedia.org\/wiki\/Multiversion_concurrency_control\" target=\"_blank\">Multiversion concurrency control<\/a><\/li><li><a href=\"https:\/\/dev.mysql.com\/doc\/refman\/8.0\/en\/innodb-index-types.html\">Clustered and Secondary Indexes<\/a><\/li><li><a rel=\"noreferrer noopener\" aria-label=\"Two-phase locking\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\" href=\"https:\/\/en.wikipedia.org\/wiki\/Two-phase_locking\" target=\"_blank\">Two-phase locking<\/a><\/li><li><a rel=\"noreferrer noopener\" aria-label=\"Isolation (database systems)\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\" href=\"https:\/\/en.wikipedia.org\/wiki\/Isolation_%28database_systems%29\" target=\"_blank\">Isolation (database systems)<\/a><\/li><li><a rel=\"noreferrer noopener\" aria-label=\"InnoDB Startup Options and System Variables\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/8.0\/en\/innodb-parameters.html\" target=\"_blank\">InnoDB Startup Options and System Variables<\/a><\/li><li><a rel=\"noreferrer noopener\" aria-label=\"Index Condition Pushdown Optimization\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.6\/en\/index-condition-pushdown-optimization.html\" target=\"_blank\">Index Condition Pushdown Optimization<\/a><\/li><li><a href=\"https:\/\/www.cnblogs.com\/crazylqy\/p\/7611069.html\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"https:\/\/www.cnblogs.com\/crazylqy\/p\/7611069.html\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\">https:\/\/www.cnblogs.com\/crazylqy\/p\/7611069.html<\/a><\/li><\/ul>\n<!-- <audio autoplay=\"autoplay\" height=\"100\" width=\"100\" hidden=\"true\"><source src=\"https:\/\/c.coka.la\/orAvPR.mp3\" type=\"audio\/mp3\"\/><\/audio><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/ws3.sinaimg.cn\/large\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/> --><p><!-- <img decoding=\"async\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/>--><img decoding=\"async\" src=\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/><\/p><p>\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01<b>\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1a<font color=\"red\">xttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p><p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a<a href=\"https:\/\/www.xttblog.com\">\u4e1a\u4f59\u8349<\/a>\uff1a &raquo; <a href=\"https:\/\/www.xttblog.com\/?p=4926\">MySQL InnoDB \u7684\u52a0\u9501\u5206\u6790<\/a><\/p><!-- <div class=\"bd-reward-stl\"><button id=\"bdRewardBtn\"><span><\/span><\/button><\/div> -->","protected":false},"excerpt":{"rendered":"<p>\u524d\u9762\u5199\u4e86\u4e00\u7bc7 MySQL \u7684 2PL \u6587\u7ae0\u300a8 \u5f20\u56fe\uff0c\u7ed9\u4f60\u5b8c\u6574\u7684\u5256\u6790 MySQL \u4e24\u9636\u6bb5\u52a0\u9501\uff082PL\uff09\u534f\u8bae\u300b\uff0c [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[1674,1968,83,1683,1682],"class_list":["post-4926","post","type-post","status-publish","format-standard","hentry","category-sql","tag-innodb","tag-mvcc","tag-mysql","tag-next-key-locks","tag-gap-locks"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4926","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4926"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4926\/revisions"}],"predecessor-version":[{"id":4927,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4926\/revisions\/4927"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4926"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4926"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4926"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}