{"id":848,"date":"2017-08-14T21:42:57","date_gmt":"2017-08-14T13:42:57","guid":{"rendered":"http:\/\/www.5x44.cn\/?p=848"},"modified":"2017-11-20T14:23:15","modified_gmt":"2017-11-20T06:23:15","slug":"mysql-innodb%e4%ba%8b%e5%8a%a1%e9%94%81","status":"publish","type":"post","link":"https:\/\/www.5x44.cn\/?p=848","title":{"rendered":"mysql InnoDB\u4e8b\u52a1\u9501"},"content":{"rendered":"<p>\u4e00\u3001\u4ec0\u4e48\u662f\u9501<\/p>\n<ol>\n<li>\u4fdd\u62a4\u6570\u636e\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027<\/li>\n<li>\u63a7\u5236\u5bf9\u5171\u4eab\u8d44\u6e90\u8fdb\u884c\u5e76\u53d1\u8bbf\u95ee<\/li>\n<\/ol>\n<p>\u4e8c\u3001\u6570\u636e\u5e93\u4e2d\u7684\u9501<\/p>\n<p>\u5206\u4e3a\u4e24\u5927\u7c7b<\/p>\n<table>\n<tbody>\n<tr>\n<td><\/td>\n<td>lock<\/td>\n<td>latch\/mutex<\/td>\n<\/tr>\n<tr>\n<td>\u5bf9\u8c61<\/td>\n<td>\u4e8b\u52a1<\/td>\n<td>\u7ebf\u7a0b<\/td>\n<\/tr>\n<tr>\n<td>\u4fdd\u62a4<\/td>\n<td>\u6570\u636e\u5e93\u903b\u8f91\u5185\u5bb9<\/td>\n<td>\u5185\u5b58\u6570\u636e\u7ed3\u6784<\/td>\n<\/tr>\n<tr>\n<td>\u6301\u7eed\u65f6\u95f4<\/td>\n<td>\u4e8b\u52a1\u7684\u8fc7\u7a0b<\/td>\n<td>\u4e34\u754c\u8d44\u6e90\u4e89\u593a<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u4e09\u3001\u4e8b\u52a1\u9501\u7c92\u5ea6<\/p>\n<ul>\n<li>\u884c\u9501\uff08InnoDB, Oracle\uff09<\/li>\n<li>\u9875\u9501\uff08SQL Server\uff09\u4e00\u9875\u53ef\u80fd\u662f\u51e0\u884c\u5927\u5c0f<\/li>\n<li>\u8868\u9501\uff08MyISAM\uff0cMemory\uff09<\/li>\n<li>\u9501\u5347\u7ea7\uff08SQL Server\u4e2d\u4f1a\u53d1\u751f\uff0c\u7531\u4e8e\u9875\u9501\u5185\u5bb9\u6bd4\u8f83\u591a\uff0c\u5347\u7ea7\u6210\u8868\u9501\uff09<\/li>\n<\/ul>\n<p>\u56db\u3001InnoDB\u4e2d\u7684\u9501\u6a21\u5f0f\u4e0e\u7c92\u5ea6<\/p>\n<table>\n<tbody>\n<tr>\n<td>\u56db\u79cd\u57fa\u672c\u9501\u6a21\u5f0f<\/td>\n<\/tr>\n<tr>\n<td>\u5171\u4eab\u9501\uff08S\uff09-\u8bfb\u9501<\/td>\n<td>\u884c\u9501<\/td>\n<\/tr>\n<tr>\n<td>\u6392\u4ed6\u9501\uff08X\uff09-\u5199\u9501<\/td>\n<td>\u884c\u9501<\/td>\n<\/tr>\n<tr>\n<td>\u610f\u5411\u5171\u4eab\u9501\uff08IS\uff09<\/td>\n<td>\u8868\u7ea7<\/td>\n<\/tr>\n<tr>\n<td>\u610f\u5411\u6392\u4ed6\u9501\uff08IX\uff09<\/td>\n<td>\u8868\u7ea7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li>\u5728\u5bf9\u8868\u4e2d\u7684\u8bb0\u5f55\u65bd\u52a0\u8bfb\u9501\u6216\u5199\u9501\u4e4b\u524d\uff0c\u9996\u5148\u4f1a\u65bd\u52a0\u610f\u5411\u8bfb\u9501\u548c\u610f\u5411\u5199\u9501\u3002<\/li>\n<li>\u610f\u5411\u9501\u662f\u544a\u8bc9\u6570\u636e\u5e93\uff0c\u5f53\u524dsession\u662f\u8981\u6dfb\u52a0\u4ec0\u4e48\u9501\uff0c\u662f\u884c\u9501\u8fd8\u662f\u8868\u9501\u3002<\/li>\n<li>\u610f\u5411\u9501\u603b\u662f\u81ea\u52a8\u65bd\u52a0\u548c\u91ca\u653e\u7684\u3002<\/li>\n<li>\u610f\u5411\u9501\u548cX\/S\u9501\u7684\u7ea7\u522b\u4e0d\u540c\uff0c\u9664\u4e86\u4f1a\u963b\u585eIX\/IS\u9501\u5916\uff0c\u4e00\u822c\u4e0d\u4f1a\u963b\u585e\u5176\u5b83\u64cd\u4f5c\uff0c\u5e76\u4e14\u5b83\u7684\u81ea\u52a8\u65bd\u52a0\u548c\u91ca\u653e\u7684\u65f6\u95f4\u975e\u5e38\u77ed<\/li>\n<\/ul>\n<p>\u4e94\u3001InnoDB\u9501\u6a21\u5f0f\u4e92\u65a5\u8868<\/p>\n<table class=\"informaltable\" border=\"1\" summary=\"Compatibility matrix showing which combinations of lock types X, IX, S, and IS are allowed. Each cell in the matrix is marked as either &quot;Compatible&quot; or &quot;Conflict&quot;.\">\n<thead>\n<tr>\n<th scope=\"col\"><\/th>\n<th scope=\"col\"><em class=\"replaceable\"><code>X<\/code><\/em><\/th>\n<th scope=\"col\"><em class=\"replaceable\"><code>IX<\/code><\/em><\/th>\n<th scope=\"col\"><em class=\"replaceable\"><code>S<\/code><\/em><\/th>\n<th scope=\"col\"><em class=\"replaceable\"><code>IS<\/code><\/em><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td scope=\"row\"><em class=\"replaceable\"><code>X<\/code><\/em><\/td>\n<td>Conflict<\/td>\n<td>Conflict<\/td>\n<td>Conflict<\/td>\n<td>Conflict<\/td>\n<\/tr>\n<tr>\n<td scope=\"row\"><em class=\"replaceable\"><code>IX<\/code><\/em><\/td>\n<td>Conflict<\/td>\n<td>Compatible<\/td>\n<td>Conflict<\/td>\n<td>Compatible<\/td>\n<\/tr>\n<tr>\n<td scope=\"row\"><em class=\"replaceable\"><code>S<\/code><\/em><\/td>\n<td>Conflict<\/td>\n<td>Conflict<\/td>\n<td>Compatible<\/td>\n<td>Compatible<\/td>\n<\/tr>\n<tr>\n<td scope=\"row\"><em class=\"replaceable\"><code>IS<\/code><\/em><\/td>\n<td>Conflict<\/td>\n<td>Compatible<\/td>\n<td>Compatible<\/td>\n<td>Compatible<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u516d\u3001\u4e00\u822cselect\u8bed\u540d\u4e0d\u4f1a\u52a0\u4efb\u4f55\u9501\uff0c\u4e5f\u4e0d\u4f1a\u88ab\u4efb\u4f55\u4e8b\u52a1\u9501\u963b\u585e\u3002<\/p>\n<ul>\n<li>select\u7684\u9694\u79bb\u6027\u7531MVCC\uff08\u8bfb\u56de\u6eda\u6bb5\uff0c\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236Multi-Version Concurrency Control\uff09\u7684\u65b9\u5f0f\u5b9e\u73b0\u3002<\/li>\n<\/ul>\n<p>\u4e03\u3001<\/p>\n<p>\uff081\uff09S\u9501<\/p>\n<p>\u624b\u52a8\u65bd\u52a0\uff1aselect * from tables<span style=\"color: #800000;\"><strong> lock in share mode<\/strong><\/span>;<\/p>\n<p>\u81ea\u52a8\u65bd\u52a0\uff1a<del>insert \u524d<\/del><\/p>\n<p>\uff082\uff09X\u9501<\/p>\n<p>\u624b\u52a8\u65bd\u52a0\uff1aselect * from tables <strong><span style=\"color: #800000;\">lock for update<\/span><\/strong>;<\/p>\n<p>\u81ea\u52a8\u65bd\u52a0\uff1aupdate, delete, insert\u524d<\/p>\n<p>\uff083\uff09\u4e8b\u52a1\u4e2d\u7528select &#8230; lock in share mode \u83b7\u5f97\u5171\u4eab\u9501\uff0c\u4e3b\u8981\u7528\u4e8e\u786e\u8ba4\u6570\u636e\u4f9d\u5b58\u5173\u7cfb\uff0c\u5e76\u786e\u4fdd\u6ca1\u6709\u4eba\u5bf9\u6570\u636e\u8fdb\u884c\u66f4\u6539\u3002\u4f46\u662f\u5982\u679c\u4e8b\u52a1\u4e5f\u8981\u5bf9\u8be5\u8bb0\u5f55\u8fdb\u884c\u66f4\u65b0\u64cd\u4f5c\uff0c\u5219\u5f88\u6709\u53ef\u80fd\u9020\u6210\u6b7b\u9501\u3002\u5f53\u6b7b\u9501\u53d1\u751f\u662fInnoDB\u4f1a\u56de\u6eda\u4ee3\u4ef7\u6bd4\u8f83\u5c0f\u7684\u4e8b\u52a1\u3002<\/p>\n<p>\uff084\uff09\u4e8b\u52a1\u7684\u63d0\u4ea4\u6216\u56de\u6eda\u53ef\u4ee5\u91ca\u653e\u9501<\/p>\n<p>\uff085\uff09\u4e00\u822c\u4e0d\u7528\u8003\u8651IX\u548cIS\u9501\uff0c\u6240\u4ee5\uff1a<\/p>\n<table>\n<tbody>\n<tr>\n<td><\/td>\n<td>X<\/td>\n<td>S<\/td>\n<\/tr>\n<tr>\n<td>X<\/td>\n<td>Conflict<\/td>\n<td>Conflict<\/td>\n<\/tr>\n<tr>\n<td>S<\/td>\n<td>Conflict<\/td>\n<td>Compatible<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\uff086\uff09\u5728innoDB\u4e2d\u7531\u4e0d\u540cSQL\u8bed\u53e5\u65bd\u52a0\u7684\u9501\uff1a<\/p>\n<p>https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/innodb-locks-set.html<\/p>\n<p>\u516b\u3001\u53d8\u91cfinnodb_lock_wait_timeout\u7528\u4e8e\u8bbe\u7f6e\u5f53\u4e00\u6761\u8bb0\u5f55\u7531\u4e8e\u9501\u7684\u539f\u56e0\u88ab\u963b\u585e\uff0c\u8981\u7b49\u591a\u957f\u65f6\u95f4\u3002\u5982\u679c\u53d1\u751f\u963b\u585e\u53ef\u4ee5\u4f7f\u7528\uff1a<br \/>\n<code>show processlist;<\/code><br \/>\n\u67e5\u770b\u963b\u585e\u8fdb\u7a0b\u3002<br \/>\n\u4e5d\u3001\u5982\u679c\u9501\u7684\u4e89\u7528\u8f83\u4e25\u91cd\uff0cinnodb_row_lock_waits\u548cinnodb_row_lock_time_avg\u7684\u503c\u4f1a\u6bd4\u8f83\u9ad8\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u547d\u4ee4\u67e5\u770b\uff1a<br \/>\n<code>show status like 'innodb_row_lock%'<\/code><\/p>\n<h2>\u5341\u3001InnoDB\u9501\u7684\u5b9e\u73b0<\/h2>\n<ol>\n<li>InnoDB\u7684\u884c\u9501\u5e76\u4e0d\u662f\u50cforacle\u4e00\u6837\u771f\u7684\u5bf9\u6bcf\u884c\u6570\u636e\u52a0\u9501\uff0cInnoDB\u7684\u9501\u5b9e\u9645\u4e0a\u662f\u52a0\u5728\u7d22\u5f15\u4e0a\u7684\u3002\u6240\u4ee5\u5982\u679c\u7d22\u5f15\u6709\u91cd\u590d\u7684\u8bdd\uff0c\u90a3\u4e48\u91cd\u590d\u7684\u884c\u4f1a\u4e00\u8d77\u88ab\u9501\u5b9a\u3002\u5982\u679c\u8868\u6ca1\u6709\u7d22\u5f15\uff0c\u90a3\u4e48\u9501\u4f1a\u52a0\u5230\u6574\u4e2a\u8868\u4e0a\u800c\u4e0d\u662f\u884c\u4e0a\u3002<strong>\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u8981\u7279\u522b\u6ce8\u610fInnoDB\u884c\u9501\u8fd9\u4e00\u7279\u6027\uff0c\u4e0d\u7136\u7684\u8bdd\u53ef\u80fd\u4f1a\u5bfc\u81f3\u5927\u91cf\u7684\u9501\u51b2\u7a81\u3002<\/strong><\/li>\n<li>\u5373\u4f7f\u8868\u4e2d\u4f7f\u7528\u4e86\u7d22\u5f15\uff0c\u4f46\u662f\u5426\u4f7f\u7528\u7d22\u5f15\u6765\u68c0\u7d22\u8bb0\u5f55\u662f\u7531MySql\u901a\u8fc7\u5224\u65ad\u4e0d\u540c\u7684<u>\u6267\u884c\u8ba1\u5212<\/u>\u7684\u4ee3\u4ef7\u6765\u51b3\u5b9a\u7684\u3002\u56e0\u4e3a\u6709\u65f6Mysql\u4f1a\u8ba4\u4e3a\u4f7f\u7528\u5168\u8868\u68c0\u67e5\u6548\u7387\u66f4\u9ad8\uff0c\u5982condition\u5217\u8fdb\u884c\u8fc7\u7c7b\u578b\u8f6c\u6362\uff0c\u90a3\u4e48\u5217\u4e0a\u7684\u7d22\u5f15\u5c31\u4e0d\u4f1a\u88ab\u4f7f\u7528\uff0c\u68c0\u67e5\u6267\u884c\u8ba1\u5212\u65b9\u6cd5\uff1a<br \/>\n<code>explain select * from table_name where condition<\/code><\/li>\n<\/ol>\n<h2>\u5341\u4e00\u3001\u5c0f\u5fc3GAP LOCK<\/h2>\n<p>\u4ec0\u4e48\u662fGAP\uff1f\u5728INNODB\u7684\u7d22\u5f15\u6570\u636e\u7ed3\u6784\u4e2d\uff0c\u80fd\u63d2\u5165\u65b0\u503c\u7684\u5730\u65b9\u5c31\u53eb\u505aGAP\uff01<\/p>\n<p>\u5f53\u6211\u4eec\u901a\u8fc7\u6761\u4ef6\u8bf7\u6c42\u5171\u4eab\uff08S\uff09\u6216\u6392\u4ed6\uff08X\uff09\u9501\u65f6\uff0c\u5f97\u5230\u7684\u7ed3\u679c\u679c\u662f\u4e00\u4e2a\u8303\u56f4\u5185\u7684\u7ed3\u679c\u96c6\uff0cInnoDB\u4f1a\u7ed9\u7b26\u5408\u6761\u4ef6\u7684\u5df2\u6709\u6570\u636e\u8bb0\u5f55\u7684\u7d22\u5f15\u9879\u52a0\u9501\uff1b\u5bf9\u4e8e\u952e\u503c\u5728\u6761\u4ef6\u8303\u56f4\u5185\u4f46\u5e76\u4e0d\u5b58\u5728\u7684\u8bb0\u5f55\uff0c\u53eb\u505a\u201c\u95f4\u9699\uff08GAP\uff09\u201d\uff0cInnoDB\u4e5f\u4f1a\u5bf9\u8fd9\u4e2a\u201c\u95f4\u9699\u201d\u52a0\u9501\uff0c\u8fd9\u79cd\u9501\u673a\u5236\u5c31\u662f\u95f4\u9699\u9501\u3002<\/p>\n<p>\u5982\u6211\u4eec\u53ea\u9501\u5b9a\u8bb0\u5f554\uff1a<\/p>\n<p>1\uff0c4\uff0c4\uff0c4\uff0c4\uff0c4\uff0c6\uff0c6\uff0c6<\/p>\n<p>\u8fd9\u65f6\u4f1a\u628a1\u81f36\u90fd\u9501\u5b9a\uff0c\u8fd9\u65f6\u60f3\u63d2\u51652\uff0c3\uff0c5\u90fd\u662f\u4e0d\u884c\u7684\u3002\u95f4\u9699\u9501\u4ea7\u751f\u7684\u65b9\u5f0f\u5f88\u591a\uff0c\u5bf9\u4e0d\u5b58\u5728\u7684\u8bb0\u5f55\u8fdb\u884c\u52a0\u9501\u4e5f\u4f1a\u5f62\u6210\u95f4\u9699\u9501\u3002\u800cmysql\u4e5f\u662f\u901a\u8fc7GAP LOCK\u5728repeatable-read\u9694\u79bb\u7ea7\u522b\u6d88\u9664\u5e7b\u8bfb\u7684\u3002<\/p>\n<p>https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/innodb-locking.html#innodb-gap-locks<br \/>\ngap lock\u662f\u4f1a\u9501\u4f4f\u7d22\u5f15\u8bb0\u5f55\u4e4b\u95f4\u7684\u201c\u95f4\u9699\u201d\uff0c\u6216\u9501\u4f4f\u7b2c\u4e00\u6761\u7d22\u5f15\u4e4b\u524d\u6216\u6700\u540e\u4e00\u6761\u7d22\u5f15\u4e4b\u540e\u3002\u4f8b\u5982\uff1a&lt;code&gt;SELECT c1 FROM t WHERE c1 BETWEEN 10 and 20 FOR UPDATE;&lt;\/code&gt;\u4e0d\u80fd\u63d2\u516515\u5230c1\u5217\uff0c\u65e0\u8bba\u662f\u5426\u6709\u5b58\u5728\u7684\u503c\u5728\u5176\u4e2d\uff0c\u56e0\u4e3a10~20\u4e4b\u524d\u7684\u201c\u95f4\u9699\u201d\u5df2\u7ecf\u4e0a\u9501\u3002<\/p>\n<p>gap\u53ef\u80fd\u5b58\u5728\u4e8e\u5355\u72ec\u7684\u7d22\u5f15\u503c\uff0c\u591a\u4e2a\u7d22\u5f15\u503c\uff0c\u751a\u81f3\u662f\u7a7a\u7d22\u5f15\u3002<\/p>\n<p>GAP LOCK\u662f\u6027\u80fd\u548c\u5e76\u884c\u5316\u7684\u6298\u4e2d\u65b9\u6848\uff0c\u5e76\u7528\u4e8e\u67d0\u4e9b\u4e8b\u52a1\u9694\u79bb\u7b49\u7ea7\u4f46\u4e0d\u662f\u6240\u6709\u7684\u90fd\u4f7f\u7528\u3002<\/p>\n<p>GAP LOCK\u5e76\u4e0d\u7528\u4e8e<strong>\u552f\u4e00<\/strong>\u7d22\u5f15\u67e5\u627e\u552f\u4e00\u884c\u7684\u65f6\u5019\uff08\u8fd9\u5e76\u4e0d\u5305\u542b\u641c\u7d22\u6761\u4ef6\u662f\u591a\u5217\u7d22\u5f15\u4e2d\u67d0\u51e0\u5217\uff1b\u5728\u8fd9\u79cd\u60c5\u51b5GAP LOCK\u8fd8\u662f\u4f1a\u53d1\u751f\uff09\u3002 \u4f8b\u5982\uff0c\u5982\u679cid\u662f<strong>\u552f\u4e00\u7d22\u5f15<\/strong><code>SELECT * FROM child WHERE id = 100 for update;<\/code>\u53ea\u9501\u4f4f\u4e00\u884c\uff0c\u5411\u5176\u5b83\u884c\u63d2\u5165\u662f\u4e0d\u4f1a\u9501\u4f4f\u7684\u3002 \u5982\u679cid\u4e0d\u662f\u7d22\u5f15\uff0c\u6216\u8005\u8fd8\u6709\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u8fd9\u6761\u8bed\u53e5\u4f1a\u9501\u4f4f\u5b83\u7684\u201c\u95f4\u9699\u201d\u3002<\/p>\n<p>\u6709\u4e00\u70b9\u503c\u5f97\u6ce8\u610f\uff0c\u4e0d\u540c\u7684\u4e8b\u52a1\u4e4b\u524d\u6ca1\u6709GAP LOCK\u9501\u51b2\u7a81\u3002\u4f8b\u5982\uff1a\u4e8b\u52a1A\u53ef\u4ee5\u5728\u4e8b\u52a1B\u5df2\u7ecf\u7ed9GAP\u4e0a\u4e86\u6392\u5b83\u9501\uff08X\uff09\u7684\u540c\u65f6\u4e0a\u4e00\u4e2a\u5171\u4eab\u9501\uff08S\uff09\u3002 \u56e0\u4e3a\u5982\u679c\u8bb0\u5f55\u4ece\u7d22\u5f15\u4e2d\u5220\u9664\uff0c\u4f46\u662f\u4e0d\u540c\u4e8b\u52a1\u8bb0\u5f55\u4e0a\u7684gap lock\u5fc5\u987b\u878d\u5408\u5230\u4e00\u8d77\u3002<\/p>\n<p>GAP LOCK\u5728InnoDB\u4e2d\u662f\u201cpurely inhibitive\u201d\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u4eec\u53ea\u662f\u505c\u6b62\u5176\u4ed6\u4e8b\u52a1\u5411GAP\u4e2d\u63d2\u5165\u6570\u636e\u3002 \u5b83\u4eec\u5e76\u4e0d\u4f1a\u963b\u6b62\u5176\u5b83\u4e8b\u52a1\u5411\u4e00\u4e2a\u76f8\u540c\u7684GAP\u4e0aGAP LOCK\u3002\u56e0\u6b64\uff0c\u4e00\u4e2a GAP X-LOCK\u548cGAP S-LOCK\u5177\u6709\u540c\u6837\u6548\u679c\u3002<\/p>\n<p>GAP LOCK\u53ef\u4ee5\u88ab\u663e\u793a\u7684\u7981\u6b62\uff0c\u5982\u679c\u4f60\u6539\u53d8\u4e86\u4e8b\u52a1\u7684\u9694\u79bb\u7ea7\u522b\u5230READ COMMITTED\u6216\u5f00\u542f innodb_locks_unsafe_for_binlog \u7cfb\u7edf\u53d8\u91cf\uff08\u8fd9\u4e2a\u503c\u73b0\u5728\u4e0d\u63a8\u8350\u4f7f\u7528\uff09\u3002\u5728\u8fd9\u4e9b\u6761\u4ef6\u4e0b\uff0cGAP LOCK\u662f\u5173\u95ed\u7684\uff0c\u4e0d\u88ab\u7528\u4e8e\u67e5\u627e\u548c\u7d22\u5f15\u626b\u63cf\uff0c\u5e76\u4e14\u53ea\u88ab\u7528\u4e8e\u5916\u952e\u7ea6\u675f\u548c\u91cd\u590d\u952e\u68c0\u67e5\u3002\uff08Under these circumstances, gap locking is disabled for searches and index scans and is used only for foreign-key constraint checking and duplicate-key checking. \uff09<\/p>\n<p>\u4f7f\u7528\u4e86 <a class=\"link\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/innodb-transaction-isolation-levels.html#isolevel_read-committed\"><code class=\"literal\">READ COMMITTED<\/code><\/a> \u9694\u79bb\u7ea7\u522b\u6216\u5f00\u542f\u4e86innodb_locks_unsafe_for_binlog\u8fd8\u6709\u5176\u5b83\u5f71\u54cd\u3002MYSQL\u8bc4\u4f30\u8fc7WHERE\u6761\u4ef6\u540e\uff0c\u5bf9\u4e8e\u4e0d\u5339\u914d\u7684\u884c\uff0c\u8bb0\u5f55\u9501\u4f1a\u88ab\u91ca\u653e\u3002\u5bf9\u4e8eUPDATE\u8bed\u53e5\uff0cInnoDB\u505a\u4e86\u4e00\u4e2a\u201c\u534a\u540c\u6b65\u201d\u8bfb\uff08semi-consistent read\uff09\uff0c\u5728\u63d0\u4ea4\u4e4b\u524d\u5c31\u5982\u540c\u8fd4\u56de\u4e86\u4e00\u4e2a\u6700\u7ec8\u63d0\u4ea4\u540e\u7684\u7248\u672c\uff0c\u4ee5\u81f3\u4e8eMYSQL\u80fd\u51b3\u5b9a\u8be5\u884c\u662f\u5426\u5339\u914d\u5230\uff08\u53e6\u4e00\u4e8b\u52a1\u7684\uff09UPDATE\u7684WHERE\u6761\u4ef6\uff08\u8bd1\u8005\u6ce8\uff1a\u4e5f\u5c31\u662f\u5728B\u4e8b\u52a1\u4e2d\u80fd\u8bfb\u5230A\u4e8b\u52a1\u63d0\u4ea4COMMIT\u540e\u7684\u7ed3\u679c\uff0c\u800c\u4e0d\u662f\u53ea\u770b\u5230\u65e7\u7684\u5feb\u7167\u3002\uff09\u3002<\/p>\n<h2>\u5341\u4e8c\u3001NEXT-KEY lock<\/h2>\n<p>next-key\u9501\u662f\u7ed3\u5408\u4e86\u7d22\u5f15\u4e0a\u7684\u8bb0\u5f55\u9501\u548c\u7d22\u5f15\u8bb0\u5f55\u4e4b\u524d\u7684gap lock\u3002<\/p>\n<p>InnoDB\u6267\u884c\u201c\u884c\u7ea7\u9501\u201d\uff0c\u5bf9\u5339\u914d\u7684\u7d22\u5f15\u8bb0\u5f55\u8bbe\u7f6e\u5171\u4eab\uff08S\uff09\u9501\u6216\u6392\u5b83\u9501\uff08X\uff09\u3002\u56e0\u6b64\uff0c\u884c\u7ea7\u9501\u5b9e\u9645\u4e0a\u662f\u7d22\u5f15\u8bb0\u5f55\u9501\u3002next-key\u9501\u540c\u6837\u5f71\u54cd\u7d22\u5f15\u8bb0\u5f55\u4e4b\u524d\u7684gap\u3002\u6240\u4ee5\uff0c\u4e00\u4e2anext-key\u9501\u662f\u4e00\u4e2a\u7d22\u5f15\u8bb0\u5f55\u9501\u52a0\u4e0a \u4e00\u4e2agap lock\u3002\u5982\u679c\u4e00\u4e2a\u4f1a\u8bdd\u5728R\u8bb0\u5f55\u4e0a\u6709\u4e00\u4e2a\u5171\u4eab\u6216\u6392\u5b83\u9501\uff0c\u53e6\u4e00\u4e2a\u4f1a\u8bdd\u4e0d\u80fd\u5728R\u8bb0\u5f55\u4e4b\u524d\uff08\u7d22\u5f15\u7684\u6392\u5e8f\u65b9\u5f0f\uff09\u7684gap\u4e0a\u63d2\u5165\u65b0\u7684\u7d22\u5f15\u8bb0\u5f55\u3002<\/p>\n<p>\u5047\u8bbe\u4e00\u4e2a\u7d22\u5f15\u5305\u542b10\uff0c11\uff0c12\u548c20\u8fd9\u51e0\u4e2a\u503c\u3002\u5bf9\u4e8e\u8fd9\u4e2a\u7d22\u5f15\u53ef\u80fd\u5b58\u5728\u7684next-key lock\u6db5\u76d6\u5982\u4e0b\u533a\u95f4\uff08\u5706\u62ec\u53f7\u4e0d\u5305\u542b\uff0c\u65b9\u62ec\u53f7\u662f\u5305\u542b\u8be5\u503c\uff09\uff1a<\/p>\n<pre class=\"programlisting line-numbers language-simple\"><code class=\" language-simple\"><span class=\"token punctuation\">(<\/span>\u8d1f\u65e0\u7a77<span class=\"token punctuation\">,<\/span> 10<span class=\"token punctuation\">]<\/span>\r\n<span class=\"token punctuation\">(<\/span>10<span class=\"token punctuation\">,<\/span> 11<span class=\"token punctuation\">]<\/span>\r\n<span class=\"token punctuation\">(<\/span>11<span class=\"token punctuation\">,<\/span> 13<span class=\"token punctuation\">]<\/span>\r\n<span class=\"token punctuation\">(<\/span>13<span class=\"token punctuation\">,<\/span> 20<span class=\"token punctuation\">]<\/span>\r\n<span class=\"token punctuation\">(<\/span>20<span class=\"token punctuation\">,<\/span> \u6b63\u65e0\u7a77<span class=\"token punctuation\">)<\/span><\/code><\/pre>\n<p>\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0cInnoDB\u64cd\u4f5c\u5728 <a class=\"link\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/innodb-transaction-isolation-levels.html#isolevel_repeatable-read\"><code class=\"literal\">REPEATABLE READ<\/code><\/a> \u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u4e0b\u3002\u5728\u8fd9\u60c5\u51b5\u4e0b\uff0cInnoDB\u4f7f\u7528next-key lock\u7528\u4e8e\u67e5\u627e\u548c\u7d22\u5f15\u626b\u63cf\uff0c\u4ece\u800c\u6d88\u9664\u4e86\u5e7b\u8bfb\u884c\u3002<\/p>\n<h2>\u5341\u4e09\u3001\u63d2\u5165\u610f\u5411\u9501<\/h2>\n<p>\u63d2\u5165\u610f\u5411\u9501\u662fgap lock\u7684\u4e00\u79cd\uff0c\u7531 <a class=\"link\" title=\"13.2.5\u00a0INSERT Syntax\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/insert.html\"><code class=\"literal\">INSERT<\/code><\/a> \u64cd\u4f5c\u5728\u63d2\u5165\u884c\u4e4b\u524d\u8bbe\u7f6e\u3002\u8fd9\u4e2a\u9501\u4fe1\u53f7\u7528\u4e8e\u5982\u679c\u591a\u4e2a\u4e8b\u52a1\u8981\u63d2\u5165\u8bb0\u5f55\u7684\u4f4d\u7f6e\u4e0d\u662f\u5728\u540c\u4e00\u4e2aGAP\uff0c\u90a3\u4e48\u65e0\u9700\u7b49\u5f85\u5176\u5b83\u4e8b\u52a1\u3002\u5047\u8bbe\u7d22\u5f15\u8bb0\u5f55\u503c\u662f4\u548c7\u3002\u4e24\u4e2a\u4e0d\u540c\u7684\u4e8b\u52a1\u610f\u56fe\u5206\u522b\u63d2\u51655\u548c6\u3002\u4e24\u4e2a\u4e8b\u52a1\u90fd\u4f1a\u9501\u4f4f4\u548c7\u4e4b\u95f4\u7684GAP\uff0c\u7528\u4e8e\u5728\u88ab\u63d2\u5165\u7684\u884c\u83b7\u5f97\u6392\u5b83\u9501\uff0c\u4f46\u662f\u56e0\u4e3a\u63d2\u5165\u7684\u884c\u6ca1\u6709\u51b2\u7a81\uff0c\u6240\u4ee5\u4e0d\u4f1a\u4e92\u76f8\u963b\u585e\u5bf9\u65b9\u3002<\/p>\n<p>\u4e0b\u9762\u7684\u4f8b\u5b50\u6f14\u793a\u4e86\u5728\u83b7\u5f97\u6392\u5b83\u9501\u4e4b\u524d\u65bd\u52a0\u63d2\u5165\u610f\u5411\u9501\u7684\u65b9\u6cd5\u3002\u4f8b\u5b50\u8c03\u7528\u4e86\u4e24\u4e2a\u5ba2\u6237\u7aefA\u548cB\u3002<\/p>\n<p>A\u521b\u5efa\u7684\u8868\u5305\u542b\u4e24\u4e2a\u7d22\u5f15\u8bb0\u5f55\uff0890\u548c102\uff09\uff0c\u7136\u540e\u5f00\u59cb\u4e00\u4e2a\u4e8b\u52a1\uff0c\u653e\u7f6e\u4e00\u4e2aID\u5927\u4e8e100\u7684\u6392\u5b83\u9501\u5728\u7d22\u5f15\u8bb0\u5f55\u4e0a\u3002\u6392\u5b83\u9501\u5305\u542b\u4e86102\u4e4b\u524d\u7684GAP LOCK\uff1a<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TABLE<\/span> child <span class=\"token punctuation\">(<\/span>id <span class=\"token datatype\">int<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">11<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">NOT<\/span> <span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">PRIMARY<\/span> <span class=\"token keyword\">KEY<\/span><span class=\"token punctuation\">(<\/span>id<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">ENGINE<\/span><span class=\"token operator\">=<\/span>InnoDB<span class=\"token punctuation\">;<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> child <span class=\"token punctuation\">(<\/span>id<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">values<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">90<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">102<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">START<\/span> <span class=\"token keyword\">TRANSACTION<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SELECT<\/span> <span class=\"token operator\">*<\/span> <span class=\"token keyword\">FROM<\/span> child <span class=\"token keyword\">WHERE<\/span> id <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">100<\/span> <span class=\"token keyword\">FOR<\/span> <span class=\"token keyword\">UPDATE<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> id  <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> 102 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span><\/code><\/pre>\n<p>B\u5f00\u59cb\u4e00\u4e2a\u4e8b\u7279\u7528\u4e8e\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\u5230GAP\u3002\u5f53\u4e8b\u52a1\u7b49\u5f85\u83b7\u5f97\u6392\u5b83\u9501\u7684\u540c\u65f6\uff0c\u4e8b\u52a1\u4f7f\u7528\u4e86\u4e00\u4e2a\u63d2\u5165\u610f\u5411\u9501\u3002<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">START<\/span> <span class=\"token keyword\">TRANSACTION<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> child <span class=\"token punctuation\">(<\/span>id<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">VALUES<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">101<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/code><\/pre>\n<p>\u63d2\u5165\u610f\u5411\u9501\u663e\u793a\u7c7b\u4f3c\u4e8eSHOW ENGINE INNODB STATUS\u7684\u8f93\u51fa\uff1a<\/p>\n<pre class=\"programlisting line-numbers  language-simple\"><code class=\" language-simple\">RECORD LOCKS space id 31 page no 3 n bits 72 index `PRIMARY` of table `test`<span class=\"token punctuation\">.<\/span>`child`\r\ntrx id 8731 lock_mode X locks gap before rec insert intention waiting\r\nRecord lock<span class=\"token punctuation\">,<\/span> heap no 3 PHYSICAL RECORD<span class=\"token operator\">:<\/span> n_fields 3<span class=\"token punctuation\">;<\/span> compact format<span class=\"token punctuation\">;<\/span> info bits 0\r\n 0<span class=\"token operator\">:<\/span> len 4<span class=\"token punctuation\">;<\/span> hex 80000066<span class=\"token punctuation\">;<\/span> asc    f<span class=\"token punctuation\">;<\/span><span class=\"token punctuation\">;<\/span>\r\n 1<span class=\"token operator\">:<\/span> len 6<span class=\"token punctuation\">;<\/span> hex 000000002215<span class=\"token punctuation\">;<\/span> asc     \" <span class=\"token punctuation\">;<\/span><span class=\"token punctuation\">;<\/span>\r\n 2<span class=\"token operator\">:<\/span> len 7<span class=\"token punctuation\">;<\/span> hex 9000000172011c<span class=\"token punctuation\">;<\/span> asc     r  <span class=\"token punctuation\">;<\/span><span class=\"token punctuation\">;<\/span><span class=\"token punctuation\">.<\/span><span class=\"token punctuation\">.<\/span><span class=\"token punctuation\">.<\/span><\/code><\/pre>\n<h2>AUTO-INC\u9501<\/h2>\n<p>AUTO-INC\u9501\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u8868\u7ea7\u9501\uff0c\u7531\u4e8b\u52a1\u63d2\u5165\u5230\u8868\u4e2d\u4ee3\u6709AUTO_INCREMENT\u7684\u5217\u65f6\u52a0\u5165\u3002\u4e3e\u4e2a\u6700\u7b80\u5355\u7684\u4f8b\u5b50\uff0c\u5982\u679c\u4e00\u4e2a\u4e8b\u52a1\u5411\u8868\u4e2d\u63d2\u5165\u503c\uff0c\u4efb\u4f55\u5176\u5b83\u4e8b\u52a1\u5fc5\u987b\u7b49\u5f85\u8bbf\u63d2\u5165\u4e8b\u4ef6\u7ed3\u675f\uff0c\u4ee5\u81f3\u4e8e\u88ab\u63d2\u5165\u7684\u884c\u8981\u7b49\u5f85\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u6536\u5230\u8fde\u7eed\u7684\u4e3b\u952e\u503c\u624d\u884c\u3002<\/p>\n<p><a class=\"link\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/innodb-parameters.html#sysvar_innodb_autoinc_lock_mode\"><code class=\"literal\">innodb_autoinc_lock_mode<\/code><\/a>\u9009\u9879\u63a7\u5236\u7740auto-increment\u9501\u4f7f\u7528\u7684\u7b97\u6cd5\u3002\u5b83\u5141\u8bb8\u4f60\u9009\u62e9\u5982\u4f55\u5bf9\u5f85\u53ef\u9884\u77e5\u7684\u81ea\u52a8\u589e\u957f\u5e8f\u5217\u548c\u6700\u5927\u5e76\u884c\u63d2\u5165\u6570\u91cf\u3002<\/p>\n<p>For more information, see <a class=\"xref\" title=\"14.8.1.5\u00a0AUTO_INCREMENT Handling in InnoDB\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/innodb-auto-increment-handling.html\">Section\u00a014.8.1.5, \u201cAUTO_INCREMENT Handling in InnoDB\u201d<\/a>.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u3001\u4ec0\u4e48\u662f\u9501 \u4fdd\u62a4\u6570\u636e\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027 \u63a7\u5236\u5bf9\u5171\u4eab\u8d44\u6e90\u8fdb\u884c\u5e76\u53d1\u8bbf\u95ee \u4e8c\u3001\u6570\u636e\u5e93\u4e2d\u7684\u9501 \u5206\u4e3a\u4e24\u5927\u7c7b lock latch\/mutex \u5bf9\u8c61 \u4e8b\u52a1 \u7ebf\u7a0b \u4fdd\u62a4 \u6570\u636e&#8230;<\/p>\n<p class=\"read-more\"><a class=\"btn btn-default\" href=\"https:\/\/www.5x44.cn\/?p=848\"> Read More<span class=\"screen-reader-text\">  Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37],"tags":[39,40],"class_list":["post-848","post","type-post","status-publish","format-standard","hentry","category-mysql","tag-innodb","tag-40"],"_links":{"self":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/848","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=848"}],"version-history":[{"count":17,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/848\/revisions"}],"predecessor-version":[{"id":1084,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/848\/revisions\/1084"}],"wp:attachment":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=848"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=848"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=848"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}