{"id":1301,"date":"2017-01-28T21:02:37","date_gmt":"2017-01-28T13:02:37","guid":{"rendered":"http:\/\/www.royalwzy.com\/?p=1301"},"modified":"2017-01-28T21:30:50","modified_gmt":"2017-01-28T13:30:50","slug":"mysql-ocp-08-%e4%ba%8b%e5%8a%a1%e4%b8%8e%e9%94%81%e5%ae%9a","status":"publish","type":"post","link":"http:\/\/www.royalwzy.com\/?p=1301","title":{"rendered":"MySQL OCP-08-\u4e8b\u52a1\u4e0e\u9501\u5b9a"},"content":{"rendered":"
—\u00a0\u4e8b\u52a1;<\/div>\n
\u5728MySQL\u4e2d,\u53ea\u6709\u90a3\u4e9b\u4f7f\u7528\u4e8b\u52a1\u5b58\u50a8\u5f15\u64ce(\u5982InnoDB)\u7684\u8868\u624d\u652f\u6301\u4e8b\u52a1;\u8fd9\u4e9b\u8bed\u53e5\u4e0d\u4f1a\u5bf9\u975e\u4e8b\u52a1\u5b58\u50a8\u5f15\u64ce\u6240\u7ba1\u7406\u7684\u8868\u4ea7\u751f\u4efb\u4f55\u660e\u663e\u5f71\u54cd;<\/div>\n
<\/div>\n
—\u00a0\u4e8b\u52a1\u6d41\u7a0b\u56fe;<\/div>\n
\u94f6\u884c\u8f6c\u8d26\u7684\u6d41\u7a0b,\u00a0\u6bd4\u5982\u7531\u4e8b\u52a1\u6765\u4fdd\u8bc1;<\/div>\n
<\/div>\n
—\u00a0ACID;<\/div>\n
1.\u5b9a\u4e49:<\/div>\n
\u00a0 \u00a0 1.Atomic(\u539f\u5b50\u6027):\u6574\u4e2a\u4e8b\u52a1\u4e8b\u52a1\u4e2d\u7684\u6240\u6709\u7684\u64cd\u4f5c\u8981\u4e0d\u5168\u90fd\u6210\u529f,\u8981\u4e0d\u5168\u90fd\u53d6\u6d88;<\/div>\n
\u00a0 \u00a0 2.Consistent(\u4e00\u81f4\u6027):\u5728\u4e8b\u52a1\u5f00\u59cb\u4e4b\u524d\u548c\u4e8b\u52a1\u7ed3\u675f\u4ee5\u540e,\u6570\u636e\u7684\u5b8c\u6574\u6027\u7ea6\u675f\u6ca1\u6709\u88ab\u7834\u574f;<\/div>\n
\u00a0 \u00a0 3.Isolated(\u9694\u79bb\u6027):\u4e24\u4e2a\u4e8b\u52a1\u7684\u6267\u884c\u662f\u4e92\u4e0d\u5e72\u6270\u7684;<\/div>\n
\u00a0 \u00a0 4.Durable(\u6301\u4e45\u6027):\u4e8b\u52a1\u5b8c\u6210\u4ee5\u540e,\u8be5\u4e8b\u52a1\u5bf9\u6570\u636e\u5e93\u6240\u6709\u7684\u64cd\u4f5c\u4fbf\u6301\u4e45\u7684\u4fdd\u5b58\u5728\u6570\u636e\u5e93\u4e2d,\u4e0d\u4f1a\u88ab\u56de\u6eda;<\/div>\n
2.\u7f3a\u70b9:\u4e8b\u52a1\u5904\u7406\u80fd\u591f\u66f4\u6709\u529b\u5730\u4fdd\u8bc1\u6570\u636e\u5e93\u64cd\u4f5c\u7684\u7ed3\u679c,\u4f46\u540c\u65f6\u4e5f\u9700\u8981\u66f4\u591a\u7684CPU\u5468\u671f,\u5185\u5b58\u548c\u78c1\u76d8\u7a7a\u95f4\u5f00\u9500;\u4e8b\u52a1\u5c5e\u6027\u5bf9\u4e8e\u67d0\u4e9b\u5e94\u7528\u7a0b\u5e8f\u6765\u8bf4\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684,\u4f46\u5e76\u975e\u6240\u6709\u5e94\u7528\u7a0b\u5e8f\u90fd\u5982\u6b64,\u60a8\u53ef\u4ee5\u9009\u62e9\u5bf9\u60a8\u7684\u5e94\u7528\u7a0b\u5e8f\u6700\u6709\u610f\u4e49\u7684\u4e8b\u52a1\u5c5e\u6027;<\/div>\n
3.\u4f7f\u7528\u573a\u666f:<\/div>\n
\u00a0 \u00a0 1.\u91d1\u878d\u7c7b\u64cd\u4f5c\u901a\u5e38\u9700\u8981\u4f7f\u7528\u4e8b\u52a1,\u4fdd\u8bc1\u6570\u636e\u5b8c\u6574\u6027\u4f1a\u6bd4\u589e\u52a0\u5f00\u9500\u6240\u5e26\u6765\u7684\u6210\u672c\u66f4\u91cd\u8981;<\/div>\n
\u00a0 \u00a0 2.\u53e6\u4e00\u65b9\u9762,\u5982\u679c\u67d0\u4e2a\u5e94\u7528\u7a0b\u5e8f\u7528\u4e8e\u8bb0\u5f55\u901a\u8fc7\u7f51\u9875\u8bbf\u95ee\u6570\u636e\u5e93\u8868\u7684\u64cd\u4f5c,\u5219\u56e0\u670d\u52a1\u5668\u4e3b\u673a\u51fa\u73b0\u6545\u969c\u800c\u4e22\u5931\u51e0\u6761\u8bb0\u5f55\u53ef\u80fd\u662f\u5141\u8bb8\u7684;<\/div>\n
<\/div>\n
—\u00a0\u4e8b\u52a1SQL\u63a7\u5236\u8bed\u53e5;<\/div>\n
1.SAVEPOINT:\u4e8b\u52a1\u4e2d\u53ef\u4ee5\u56de\u6eda\u5230\u7684\u4f4d\u7f6e\u7684\u552f\u4e00\u6807\u8bc6\u7b26;<\/div>\n
2.ROLLBACK\u00a0TO\u00a0SAVEPOINT:\u56de\u6eda\u4e4b\u540e,savepoint\u4ecd\u7136\u5b58\u5728,\u4ece\u800c\u53ef\u4ee5\u201c\u91cd\u7528\u201d\u5b83;<\/div>\n
3.RELEASE\u00a0SAVEPOINT:\u4e0d\u4f1a\u5220\u9664\u4efb\u4f55\u4e8b\u52a1\u8bed\u53e5;<\/div>\n
<\/div>\n
—\u00a0SQL\u63a7\u5236\u8bed\u53e5\u6d41\u7a0b:\u793a\u4f8b;<\/div>\n
mysql>\u00a0SET\u00a0AUTOCOMMIT\u00a0=\u00a0ON;<\/div>\n
mysql>\u00a0CREATE\u00a0TABLE\u00a0t_trans(id\u00a0INT,\u00a0comment\u00a0VARCHAR(50));<\/div>\n
mysql>\u00a0BEGIN;<\/div>\n
mysql>\u00a0SAVEPOINT\u00a0sv_bgn;<\/div>\n
mysql>\u00a0INSERT\u00a0INTO\u00a0t_trans\u00a0VALUES(1,\u00a0‘first\u00a0record!’);<\/div>\n
mysql>\u00a0SELECT\u00a0*\u00a0FROM\u00a0t_trans;<\/div>\n
mysql>\u00a0SAVEPOINT\u00a0sv_ins;<\/div>\n
mysql>\u00a0INSERT\u00a0INTO\u00a0t_trans\u00a0VALUES(2,\u00a0‘second\u00a0record!’);<\/div>\n
mysql>\u00a0UPDATE\u00a0t_trans\u00a0SET\u00a0comment\u00a0=\u00a0‘after\u00a0update’\u00a0WHERE\u00a0id\u00a0=\u00a02;<\/div>\n
mysql>\u00a0SAVEPOINT\u00a0sv_upd;<\/div>\n
mysql>\u00a0SELECT\u00a0*\u00a0FROM\u00a0t_trans;<\/div>\n
mysql>\u00a0ROLLBACK\u00a0TO\u00a0sv_ins;<\/div>\n
mysql>\u00a0SELECT\u00a0*\u00a0FROM\u00a0t_trans;<\/div>\n
mysql>\u00a0ROLLBACK\u00a0TO\u00a0sv_bgn;<\/div>\n
mysql>\u00a0SELECT\u00a0*\u00a0FROM\u00a0t_trans;<\/div>\n
mysql>\u00a0COMMIT;<\/div>\n
<\/div>\n
TIPS:<\/div>\n
1.START\u00a0TRANSACTION\u6216BEGIN:\u4e8b\u52a1\u6253\u5f00,\u76f4\u5230\u901a\u8fc7COMMIT\u6216ROLLBACK\u663e\u5f0f\u5173\u95ed;<\/div>\n
2.\u4e8b\u52a1\u7ed3\u675f\u4e4b\u540e\/ROLLBACK\u5230\u4fdd\u5b58\u70b9\u4e4b\u524d\u7684\u4fdd\u5b58\u70b9\u90fd\u4f1a\u88ab\u81ea\u52a8\u5220\u9664;<\/div>\n
<\/div>\n
—\u00a0AUTOCOMMIT\u6a21\u5f0f;<\/div>\n
1.\u542f\u7528AUTOCOMMIT\u540e,\u6bcf\u4e2a\u8bed\u53e5\u4ecd\u4f1a\u4ee5\u539f\u5b50\u65b9\u5f0f\u6267\u884c(\u9690\u5f0f\u63d0\u4ea4);\u800c\u4e0d\u662f\u6ca1\u6709\u4e8b\u52a1;<\/div>\n
2.\u53ef\u4ee5\u901a\u8fc7\u5728\u63d2\u5165\u591a\u4e2a\u884c\u65f6\u6bd4\u8f83\u8fdd\u53cd\u7ea6\u675f\u9650\u5236\u7684\u6548\u679c,\u4fbf\u53ef\u770b\u51fa\u542f\u7528AUTOCOMMIT\u548c\u6839\u672c\u4e0d\u5177\u6709\u4e8b\u52a1\u4e4b\u95f4\u7684\u5dee\u522b;\u5728\u975e\u4e8b\u52a1\u8868(\u5982MyISAM)\u4e2d,\u4e00\u65e6\u53d1\u751f\u9519\u8bef,\u8bed\u53e5\u5c31\u4f1a\u7ec8\u6b62,\u5df2\u7ecf\u63d2\u5165\u7684\u884c\u4f1a\u4fdd\u7559\u5728\u8be5\u8868\u4e2d;\u800c\u5bf9\u4e8eInnoDB\u8868,\u5df2\u7ecf\u63d2\u5165\u7684\u6240\u6709\u884c\u90fd\u4f1a\u4ece\u8be5\u8868\u4e2d\u5220\u9664,\u4ece\u800c\u4e0d\u4f1a\u4ea7\u751f\u4efb\u4f55\u5b9e\u9645\u5f71\u54cd;<\/div>\n
\u00a0 \u00a0 INSERT\u00a0INTO\u00a0t\u00a0VALUES(1),(‘x’);<\/div>\n
<\/div>\n
—\u00a0\u9690\u5f0f\u63d0\u4ea4;<\/div>\n
1.\u5bfc\u81f4\u9690\u5f0f\u63d0\u4ea4\u8bed\u53e5\u7684\u884c\u4e3a\u5c31\u50cf\u5728\u6267\u884c\u5b9e\u9645\u8bed\u53e5\u4e4b\u524d\u53d1\u51faCOMMIT\u4e00\u6837;<\/div>\n
2.\u8fd9\u4e9b\u8bed\u53e5\u672c\u8eab\u5e76\u975e\u4e8b\u52a1\u8bed\u53e5,\u4e5f\u5c31\u662f\u8bf4,\u5982\u679c\u6210\u529f,\u5219\u65e0\u6cd5\u56de\u6eda;<\/div>\n
<\/div>\n
—\u00a0\u4e8b\u52a1\u5b58\u50a8\u5f15\u64ce;<\/div>\n
1.\u4f7f\u7528SHOW\u00a0ENGINES\\G\u8bed\u53e5\u53ef\u4ee5\u5217\u51fa\u6240\u6709\u5df2\u7f16\u8bd1\u5230MySQL\u670d\u52a1\u5668\u4e2d\u7684\u5f15\u64ce;<\/div>\n
2.\u76f8\u5173\u4fe1\u606f:<\/div>\n
\u00a0 \u00a0 1.Engine:\u5f15\u64ce\u540d\u5b57;<\/div>\n
\u00a0 \u00a0 2.Support:\u503c\u4e3aYES\u6216NO,\u7528\u4e8e\u6307\u793a\u8be5\u5f15\u64ce\u662f\u5426\u53ef\u4ee5\u4f7f\u7528;\u5982\u679c\u8be5\u503c\u4e3aDISABLED,\u5219\u8868\u793a\u8be5\u5f15\u64ce\u5b58\u5728,\u4f46\u5df2\u5173\u95ed;\u503cDEFAULT\u7528\u4e8e\u6307\u793a\u670d\u52a1\u5668\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u4f7f\u7528\u7684\u5b58\u50a8\u5f15\u64ce;<\/div>\n
\u00a0 \u00a0 3.Comment:\u76f8\u5173\u7684\u4ecb\u7ecd;<\/div>\n
\u00a0 \u00a0 4.Transactions,XA\u548cSavepoints\u5217\u7528\u4e8e\u6307\u793a\u8be5\u5b58\u50a8\u5f15\u64ce\u662f\u5426\u652f\u6301\u8fd9\u4e9b\u529f\u80fd;<\/div>\n
<\/div>\n
—\u00a0\u4e8b\u52a1\u9694\u79bb\u95ee\u9898;<\/div>\n
1.\u524d\u63d0:\u670d\u52a1\u5668\u53ef\u80fd\u540c\u65f6\u5177\u6709\u591a\u4e2a\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1(\u6bcf\u4e2a\u4f1a\u8bdd\u6700\u591a\u4e00\u4e2a\u4e8b\u52a1),\u5f53\u591a\u4e2a\u5ba2\u6237\u673a\u5e76\u53d1\u8bbf\u95ee\u540c\u4e00\u4e2a\u8868\u7684\u6570\u636e\u65f6,\u53ef\u80fd\u4f1a\u51fa\u73b0\u4e00\u81f4\u6027\u95ee\u9898;<\/div>\n
2.\u201c\u810f\u201d\u8bfb:\u4e00\u4e2a\u4e8b\u52a1\u8bfb\u53d6\u53e6\u4e00\u4e2a\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539;eg:\u5047\u5b9a\u4e8b\u52a1T1\u4fee\u6539\u4e86\u67d0\u884c,\u5982\u679c\u4e8b\u52a1T2\u8bfb\u53d6\u8be5\u884c,\u5e76\u53d1\u73b0\u4fee\u6539\u5185\u5bb9,\u4f46T1\u5c1a\u672a\u63d0\u4ea4,\u5219\u4f1a\u51fa\u73b0\u201c\u810f\u201d\u8bfb\u95ee\u9898;\u4e4b\u6240\u4ee5\u4f1a\u6210\u4e3a\u4e00\u4e2a\u95ee\u9898,\u662f\u56e0\u4e3a\u5982\u679cT1\u56de\u6eda,\u6240\u505a\u7684\u66f4\u6539\u4f1a\u88ab\u64a4\u6d88,\u4f46T2\u5e76\u4e0d\u4f1a\u610f\u8bc6\u5230\u8fd9\u4e00\u70b9;<\/div>\n
3.\u4e0d\u53ef\u91cd\u590d\u8bfb:\u6307\u539f\u59cb\u6570\u636e\u4e0d\u53ef\u91cd\u590d\u8bfb;\u8868\u793a\u4e00\u4e2a\u4e8b\u52a1\u5185\u7684\u591a\u4e2a\u76f8\u540c\u67e5\u8be2\u8fd4\u56de\u4e86\u4e0d\u540c\u7684\u7ed3\u679c\u96c6;eg:\u4e8b\u52a1T1\u5185\u6709\u4e24\u6b21\u5bf9\u8868t1\u7684\u67e5\u8be2,\u4f46\u662f\u5728\u67e5\u8be2\u7684\u95f4\u9699\u4e8b\u52a1T2\u5bf9\u8868\u505a\u4e86\u66f4\u65b0,\u7ed3\u679c\u5bfc\u81f4\u7b2c\u4e8c\u6b21\u67e5\u8be2\u8ddf\u7b2c\u4e00\u6b21\u67e5\u8be2\u7684\u7ed3\u679c\u4e0d\u540c;(InnoDB\u4f7f\u7528\u5feb\u7167\u6765\u5b8c\u6210)<\/div>\n
4.\u865a\u8bfb(\u5e7b\u8bfb):\u5047\u5b9a\u4e8b\u52a1T1\u548cT2\u5f00\u59cb,\u5e76\u4e14\u5728\u4e8b\u52a1T1\u7684\u4e00\u6b21\u8bfb\u53d6\u6216\u8005\u66f4\u65b0\u4e86\u67d0\u4e9b\u884c,\u6b64\u65f6\u5982\u679c\u4e8b\u52a1T2\u63d2\u5165\u4e00\u4e2a\u65b0\u884c,\u800c\u4e8b\u52a1T1\u8bfb\u53d6\u6216\u8005\u66f4\u65b0\u64cd\u4f5c\u65f6\u53d1\u73b0\u8be5\u884c,\u5219\u4f1a\u53d1\u751f\u865a\u8bfb\u95ee\u9898(\u65b0\u884c\u4f1a\u6210\u4e3a\u865a\u884c);<\/div>\n
<\/div>\n
—\u00a0\u9694\u79bb\u7ea7\u522b;<\/div>\n
1.\u5982\u679c\u4e00\u4e2a\u5ba2\u6237\u673a\u7684\u4e8b\u52a1\u66f4\u6539\u4e86\u6570\u636e,\u5176\u4ed6\u5ba2\u6237\u673a\u7684\u4e8b\u52a1\u662f\u5e94\u53d1\u73b0\u8fd9\u4e9b\u66f4\u6539\u8fd8\u662f\u5e94\u4e0e\u5176\u9694\u79bb?\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u53ef\u4ee5\u786e\u5b9a\u540c\u65f6\u8fdb\u884c\u7684\u4e8b\u52a1\u5728\u8bbf\u95ee\u76f8\u540c\u6570\u636e\u65f6\u5f7c\u6b64\u4ea4\u4e92\u7684\u65b9\u5f0f;<\/div>\n
2.\u4f7f\u7528\u5b58\u50a8\u5f15\u64ce\u53ef\u5b9e\u73b0\u9694\u79bb\u7ea7\u522b,\u9694\u79bb\u7ea7\u522b\u9009\u9879\u5728\u4e0d\u540c\u7684\u6570\u636e\u5e93\u670d\u52a1\u5668\u4e4b\u95f4\u662f\u4e0d\u4e00\u6837\u7684,\u56e0\u6b64,InnoDB\u6240\u5b9e\u73b0\u7684\u7ea7\u522b\u53ef\u80fd\u4e0e\u5176\u4ed6\u6570\u636e\u5e93\u7cfb\u7edf\u6240\u5b9e\u73b0\u7684\u7ea7\u522b\u5e76\u4e0d\u5b8c\u5168\u5bf9\u5e94;<\/div>\n
3.InnoDB\u53ef\u5b9e\u73b0\u56db\u79cd\u9694\u79bb\u7ea7\u522b,\u7528\u4e8e\u63a7\u5236\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539\u5728\u591a\u5927\u7a0b\u5ea6\u4e0a\u53ef\u7531\u5176\u4ed6\u540c\u65f6\u8fdb\u884c\u7684\u4e8b\u52a1\u6ce8\u610f\u5230:<\/div>\n
\u00a0 \u00a0 1.READ\u00a0UNCOMMITTED:\u5141\u8bb8\u53d1\u751f\u201c\u810f\u201d\u8bfb,\u4e0d\u53ef\u91cd\u590d\u8bfb\u548c\u865a\u8bfb;<\/div>\n
\u00a0 \u00a0 2.READ\u00a0COMMITTED:\u5141\u8bb8\u53d1\u751f\u4e0d\u53ef\u91cd\u590d\u8bfb\u548c\u865a\u8bfb;\u672a\u63d0\u4ea4\u7684\u66f4\u6539\u4ecd\u4e0d\u53ef\u89c1;(Oracle\u9ed8\u8ba4)<\/div>\n
\u00a0 \u00a0 3.REPEATABLE\u00a0READ:\u65e0\u8bba\u5176\u4ed6\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539\u662f\u5426\u5df2\u63d0\u4ea4,\u4e24\u6b21\u90fd\u4f1a\u83b7\u5f97\u76f8\u540c\u7684\u7ed3\u679c;\u6362\u53e5\u8bdd\u8bf4,\u4e5f\u5c31\u662f\u4e0d\u540c\u7684\u4e8b\u52a1\u4f1a\u5bf9\u76f8\u540c\u7684\u6570\u636e\u4ea7\u751f\u4e00\u81f4\u7684\u7ed3\u679c;(InnoDB\u9ed8\u8ba4)<\/div>\n
\u00a0 \u00a0 4.SERIALIZABLE:\u4e0eREPEATABLE\u00a0READ\u7c7b\u4f3c,\u4f46\u5176\u9650\u5236\u6027\u66f4\u5f3a,\u5373\u4e00\u4e2a\u4e8b\u52a1\u6240\u9009\u7684\u884c\u4e0d\u80fd\u7531\u5176\u4ed6\u4e8b\u52a1\u66f4\u6539,\u76f4\u5230\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u5b8c\u6210\u4e3a\u6b62;<\/div>\n
4.\u9694\u79bb\u7ea7\u522b\u8d8a\u9ad8,\u5e76\u53d1\u6027\u80fd\u8d8a\u5dee;<\/div>\n
<\/div>\n
—\u00a0\u9694\u79bb\u7ea7\u522b\u95ee\u9898;<\/div>\n
—\u00a0\u8bbe\u7f6e\u9694\u79bb\u7ea7\u522b;<\/div>\n
1.\u5728\u9009\u9879\u6587\u4ef6\u6216\u8005\u547d\u4ee4\u884c\u53ef\u4ee5\u8bbe\u7f6e\u7684\u53c2\u6570\u503c\u4e3a:transaction-isolation\u00a0=\u00a0[READ-UNCOMMITTED\u00a0|\u00a0READ-COMMITTED\u00a0|\u00a0REPEATABLE-READ\u00a0|\u00a0SERIALIZABLE];<\/div>\n
2.\u5bf9\u4e8eSET\u00a0TRANSACTION\u00a0ISOLATION\u00a0LEVEL\u8bed\u53e5,\u53ef\u4ee5\u8bbe\u7f6e\u7684\u53c2\u6570\u503c\u4e3a:SET\u00a0TRANSACTION\u00a0ISOLATION\u00a0LEVEL\u00a0[READ\u00a0UNCOMMITTED\u00a0|\u00a0READ\u00a0COMMITTED\u00a0|\u00a0REPEATABLE\u00a0READ\u00a0|\u00a0SERIALIZABLE];<\/div>\n
3.\u6b64\u4e8b\u52a1\u7ea7\u522b\u53ef\u4ee5\u5168\u5c40\u8bbe\u7f6e,\u4e5f\u53ef\u4ee5\u6309\u4f1a\u8bdd\u8bbe\u7f6e,\u5982\u679c\u6ca1\u6709\u663e\u5f0f\u6307\u5b9a,\u5219\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u5c06\u6309\u4f1a\u8bdd\u8fdb\u884c\u8bbe\u7f6e;<\/div>\n
4.\u8bbe\u7f6e\u7684\u5168\u5c40\u9ed8\u8ba4\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u9002\u7528\u4e8e\u4ece\u8bbe\u7f6e\u65f6\u8d77\u6240\u6709\u65b0\u5efa\u7acb\u7684\u5ba2\u6237\u673a\u8fde\u63a5,\u73b0\u6709\u8fde\u63a5\u4e0d\u53d7\u5f71\u54cd;<\/div>\n
eg:<\/div>\n
\u00a0 \u00a0 SET\u00a0GLOBAL\u00a0TRANSACTION\u00a0ISOLATION\u00a0LEVEL\u00a0READ\u00a0COMMITTED;<\/div>\n
\u00a0 \u00a0 SET\u00a0@@global.tx_isolation\u00a0=\u00a0‘READ-COMMITTED’;<\/div>\n
<\/div>\n
—\u00a0\u5168\u5c40\u9694\u79bb\u7ea7\u522b;<\/div>\n
1.\u5ba2\u6237\u673a\u59cb\u7ec8\u53ef\u4ee5\u4fee\u6539\u5176\u81ea\u8eab\u4f1a\u8bdd\u7684\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b,\u4f46\u8981\u66f4\u6539\u5168\u5c40\u9ed8\u8ba4\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b,\u5219\u9700\u8981SUPER\u7279\u6743;<\/div>\n
2.\u67e5\u770b\u5f53\u524d\u9694\u79bb\u7ea7\u522b,\u53ef\u4f7f\u7528tx_isolation\u670d\u52a1\u5668\u53d8\u91cf;<\/div>\n
\u00a0 \u00a0 1.\u67e5\u770b\u5f53\u524d\u4f1a\u8bdd:SELECT\u00a0@@tx_isolation;<\/div>\n
\u00a0 \u00a0 2.\u67e5\u770b\u5168\u5c40\u548c\u4f1a\u8bdd:SELECT\u00a0@@global.tx_isolation,\u00a0@@session.tx_isolation;<\/div>\n
\u5982\u679c\u6b64\u53d8\u91cf\u672a\u4f7f\u7528\u524d\u7f00,\u5219\u4f1a\u8fd4\u56de\u4f1a\u8bdd\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u3002\u4f7f\u7528\u00a0global\u00a0\u548c\u00a0session\u00a0\u524d\u7f00,\u00a0\u53ef\u4ee5\u76f8\u5e94\u5730\u663e\u5f0f\u83b7\u53d6\u5168\u5c40\u6216\u4f1a\u8bdd\u9694\u79bb\u7ea7\u522b\u3002<\/div>\n
\u4e5f\u53ef\u4ee5\u4f7f\u7528\u6b64\u670d\u52a1\u5668\u53d8\u91cf\u6765\u8bbe\u7f6e\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u3002\u6b64\u9694\u79bb\u7ea7\u522b\u4e0e\u5728SET\u00a0TRANSACTION\u00a0ISOLATION\u00a0LEVEL\u8bed\u6cd5\u4e2d\u8bbe\u7f6e\u7684\u9694\u79bb\u7ea7\u522b\u540c\u6837\u6709\u6548,\u5176\u5dee\u522b\u5728\u4e8e,\u5b83\u5fc5\u987b\u4ee5\u5b57\u7b26\u4e32\u5f62\u5f0f\u00a0(\u800c\u4e0d\u662f\u666e\u901a\u5173\u952e\u5b57)\u6765\u8868\u793a,\u5e76\u4e14\u5fc5\u987b\u7528\u8fde\u5b57\u7b26(\u77ed\u5212\u7ebf\u6216\u51cf\u53f7)\u6765\u5206\u9694\u7528\u4e8e\u5b9a\u4e49\u9694\u79bb\u00a0\u7ea7\u522b\u7684\u8bcd,\u800c\u4e0d\u662f\u4f7f\u7528\u7a7a\u683c\u6765\u5206\u9694<\/div>\n
<\/div>\n
—\u00a0\u4e8b\u52a1\u793a\u4f8b:\u9694\u79bb;<\/div>\n
mysql>\u00a0PROMPT\u00a0s1><\/div>\n
s1>\u00a0SET\u00a0GLOBAL\u00a0TRANSACTION\u00a0ISOLATION\u00a0LEVEL\u00a0READ\u00a0COMMITTED;<\/div>\n
s1>\u00a0SELECT\u00a0@@global.tx_isolation;<\/div>\n
+———————–+<\/div>\n
|\u00a0@@global.tx_isolation\u00a0|<\/div>\n
+———————–+<\/div>\n
|\u00a0READ-COMMITTED\u00a0 \u00a0 \u00a0 \u00a0 |<\/div>\n
+———————–+<\/div>\n
<\/div>\n
mysql>\u00a0PROMPT\u00a0s2><\/div>\n
s2>\u00a0START\u00a0TRANSACTION;<\/div>\n
s2>\u00a0USE\u00a0db1;<\/div>\n
s2>\u00a0INSERT\u00a0INTO\u00a0t1\u00a0VALUES(1);<\/div>\n
<\/div>\n
s1>\u00a0SELECT\u00a0*\u00a0FROM\u00a0t1;<\/div>\n
Empty\u00a0Set\u00a0(0.0\u00a0sec)<\/div>\n
s2>\u00a0COMMIT;<\/div>\n
s1>\u00a0SELECT\u00a0*\u00a0FROM\u00a0t1;<\/div>\n
+——+<\/div>\n
|\u00a0id\u00a0 \u00a0|<\/div>\n
+——+<\/div>\n
|\u00a0 \u00a0 1\u00a0|<\/div>\n
+——+<\/div>\n
<\/div>\n
—\u00a0\u9501\u5b9a\u6982\u5ff5;<\/div>\n
1.\u9501\u5b9a\u673a\u5236\u53ef\u4ee5\u9632\u6b62\u56e0\u591a\u4e2a\u5ba2\u6237\u673a\u540c\u65f6\u8bbf\u95ee\u6570\u636e\u800c\u51fa\u73b0\u7684\u95ee\u9898;\u8be5\u673a\u5236\u4f1a\u4ee5\u67d0\u4e2a\u5ba2\u6237\u673a\u7684\u8eab\u4efd\u9501\u5b9a\u6570\u636e,\u4ee5\u9650\u5236\u5176\u4ed6\u5ba2\u6237\u673a\u8bbf\u95ee\u8be5\u6570\u636e,\u76f4\u5230\u91ca\u653e\u9501\u5b9a\u4e3a\u6b62;<\/div>\n
2.\u8be5\u9501\u5b9a\u5141\u8bb8\u6301\u6709\u9501\u7684\u5ba2\u6237\u673a\u8bbf\u95ee\u6570\u636e,\u800c\u9650\u5236\u4e0e\u4e4b\u4e89\u7528\u8bbf\u95ee\u6743\u9650\u7684\u5176\u4ed6\u5ba2\u6237\u673a\u53ef\u4ee5\u6267\u884c\u7684\u64cd\u4f5c,\u9501\u5b9a\u673a\u5236\u7684\u7ed3\u679c\u662f,\u5c06\u5bf9\u6570\u636e\u7684\u8bbf\u95ee\u5e8f\u5217\u5316,\u8fd9\u6837,\u5728\u591a\u4e2a\u5ba2\u6237\u673a\u8981\u6267\u884c\u76f8\u4e92\u51b2\u7a81\u7684\u64cd\u4f5c\u65f6,\u6bcf\u4e2a\u5ba2\u6237\u673a\u90fd\u5fc5\u987b\u8f6e\u6d41\u7b49\u5f85;<\/div>\n
3.\u5e76\u975e\u6240\u6709\u7c7b\u578b\u7684\u5e76\u53d1\u8bbf\u95ee\u90fd\u4f1a\u4ea7\u751f\u51b2\u7a81,\u56e0\u6b64,\u5141\u8bb8\u5ba2\u6237\u673a\u8bbf\u95ee\u6570\u636e\u6240\u9700\u7684\u9501\u5b9a\u7c7b\u578b\u53d6\u51b3\u4e8e\u8be5\u5ba2\u6237\u673a\u662f\u5e0c\u671b\u8bfb\u53d6\u8fd8\u662f\u5e0c\u671b\u5199\u5165:<\/div>\n
\u00a0 \u00a0 1.\u5982\u679c\u67d0\u4e2a\u5ba2\u6237\u673a\u5e0c\u671b\u8bfb\u53d6\u6570\u636e,\u5219\u5e0c\u671b\u8bfb\u53d6\u76f8\u540c\u6570\u636e\u7684\u5176\u4ed6\u5ba2\u6237\u673a\u4e0d\u4f1a\u4ea7\u751f\u51b2\u7a81,\u5b83\u4eec\u53ef\u4ee5\u540c\u65f6\u8fdb\u884c\u8bfb\u53d6;\u4f46\u662f,\u5982\u679c\u53e6\u4e00\u4e2a\u5ba2\u6237\u673a\u5e0c\u671b\u5199\u5165(\u4fee\u6539)\u6570\u636e,\u5219\u5b83\u5fc5\u987b\u7b49\u5f85,\u76f4\u5230\u8bfb\u53d6\u5b8c\u6210\u4e3a\u6b62;<\/div>\n
\u00a0 \u00a0 2.\u5982\u679c\u67d0\u4e2a\u5ba2\u6237\u673a\u5e0c\u671b\u5199\u5165\u6570\u636e,\u5219\u6240\u6709\u5176\u4ed6\u5ba2\u6237\u673a\u90fd\u5fc5\u987b\u7b49\u5f85,\u76f4\u5230\u5199\u5165\u5b8c\u6210,\u800c\u65e0\u8bba\u8fd9\u4e9b\u5ba2\u6237\u673a\u662f\u60f3\u8bfb\u53d6\u8fd8\u662f\u60f3\u5199\u5165;<\/div>\n
\u00a0 \u00a0 3.\u901a\u8fc7\u5171\u4eab\u9501\u548c\u4e92\u65a5\u9501\u6765\u5b8c\u6210;<\/div>\n
4.\u9501\u5b9a\u53ef\u4ee5\u7981\u6b62\u5e76\u53d1\u8fdb\u884c\u76f8\u4e92\u51b2\u7a81\u7684\u66f4\u6539\u5e76\u7981\u6b62\u8bfb\u53d6\u6b63\u5728\u66f4\u6539\u7684\u6570\u636e,\u4ece\u800c\u53ef\u4ee5\u9632\u6b62\u6570\u636e\u635f\u574f;<\/div>\n
<\/div>\n
—\u00a0\u663e\u5f0f\u884c\u9501;<\/div>\n
1.InnoDB\u652f\u6301\u4e24\u79cd\u9501\u5b9a\u4fee\u9970\u7b26,\u8fd9\u4e24\u79cd\u4fee\u9970\u7b26\u53ef\u4ee5\u6dfb\u52a0\u5230SELECT\u8bed\u53e5\u7684\u672b\u5c3e:<\/div>\n
\u00a0 \u00a0 1.LOCK\u00a0IN\u00a0SHARE\u00a0MODE\u5b50\u53e5:\u5171\u4eab\u9501,\u4e5f\u5c31\u662f\u8bf4,\u867d\u7136\u4efb\u4f55\u5176\u4ed6\u4e8b\u52a1\u90fd\u65e0\u6cd5\u83b7\u5f97\u4e92\u65a5\u9501,\u4f46\u5176\u4ed6\u4e8b\u52a1\u53ef\u4ee5\u540c\u65f6\u4f7f\u7528\u5171\u4eab\u9501;\u7531\u4e8e\u6b63\u5e38\u8bfb\u53d6\u4e0d\u4f1a\u9501\u5b9a\u4efb\u4f55\u5185\u5bb9,\u56e0\u6b64\u5b83\u4eec\u4e0d\u4f1a\u53d7\u9501\u5b9a\u7684\u5f71\u54cd;<\/div>\n
\u00a0 \u00a0 2.FOR\u00a0UPDATE\u5b50\u53e5:\u4f7f\u7528\u4e92\u65a5\u9501\u6765\u9501\u5b9a\u9009\u5b9a\u7684\u6bcf\u4e00\u884c,\u4ee5\u9632\u6b62\u5176\u4ed6\u5bf9\u8c61\u83b7\u5f97\u8fd9\u4e9b\u884c\u4e0a\u7684\u4efb\u4f55\u9501,\u4f46\u5141\u8bb8\u8bfb\u53d6\u8fd9\u4e9b\u884c;<\/div>\n
2.\u5728REPEATABLE\u00a0READ\u9694\u79bb\u7ea7\u522b\u4e2d,\u53ef\u4ee5\u5c06LOCK\u00a0IN\u00a0SHARE\u00a0MODE\u6dfb\u52a0\u5230SELECT\u64cd\u4f5c\u4e2d,\u8fd9\u6837,\u5982\u679c\u5176\u4ed6\u4e8b\u52a1\u60f3\u4fee\u6539\u9009\u5b9a\u884c,\u5219\u5b83\u4eec\u5fc5\u987b\u7b49\u5f85\u5f53\u524d\u4e8b\u52a1\u5b8c\u6210;\u8fd9\u4e00\u70b9\u4e0eSERIALIZABLE\u9694\u79bb\u7ea7\u522b\u7684\u5de5\u4f5c\u65b9\u5f0f\u7c7b\u4f3c;<\/div>\n
3.\u5bf9\u4e8e\u8be5\u9694\u79bb\u7ea7\u522b,InnoDB\u4f1a\u9690\u5f0f\u5c06LOCK\u00a0IN\u00a0SHARE\u00a0MODE\u6dfb\u52a0\u5230SELECT\u8bed\u53e5\u4e2d,\u800c\u4e0d\u4f1a\u5305\u542b\u4efb\u4f55\u663e\u5f0f\u9501\u5b9a\u4fee\u9970\u7b26;\u5982\u679c\u9009\u62e9\u4e86\u5728\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u4e2d\u4fee\u6539\u7684\u884c,\u5219\u4f1a\u9501\u5b9aSELECT,\u76f4\u5230\u8be5\u4e8b\u52a1\u63d0\u4ea4\u4e3a\u6b62;<\/div>\n
<\/div>\n
—\u00a0\u6b7b\u9501;<\/div>\n
1.\u53d1\u751f\u6b7b\u9501\u7684\u539f\u56e0:<\/div>\n
\u00a0 \u00a0 1.\u4e8b\u52a1\u9700\u8981\u83b7\u5f97\u591a\u4e2a\u8868\u4e0a\u7684\u9501\u5b9a,\u4f46\u987a\u5e8f\u76f8\u53cd;<\/div>\n
\u00a0 \u00a0 2.\u6bcf\u4e2a\u4e8b\u52a1\u56e0\u8ba1\u65f6\u95ee\u9898\u800c\u4ec5\u83b7\u53d6\u4e86\u90e8\u5206\u9501\u5b9a;<\/div>\n
2.\u5904\u7406\u529e\u6cd5:InnoDB\u4f1a\u68c0\u6d4b\u5e76\u4e2d\u6b62(\u56de\u6eda)\u5176\u4e2d\u4e00\u4e2a\u4e8b\u52a1,\u5e76\u5141\u8bb8\u53e6\u4e00\u4e2a\u4e8b\u52a1\u5b8c\u6210;<\/div>\n
\u00a0 \u00a0 1.\u5982\u679cInnoDB\u5bf9\u67d0\u4e2a\u4e8b\u52a1\u6267\u884c\u5b8c\u6574\u56de\u6eda,\u5219\u8be5\u4e8b\u52a1\u6240\u8bbe\u7f6e\u7684\u6240\u6709\u9501\u5b9a\u90fd\u4f1a\u88ab\u91ca\u653e;<\/div>\n
\u00a0 \u00a0 2.\u4f46\u662f,\u5982\u679c\u56e0\u51fa\u73b0\u9519\u8bef\u800c\u4ec5\u56de\u6eda\u4e86\u4e00\u4e2aSQL\u8bed\u53e5,\u5219\u8be5\u8bed\u53e5\u6240\u8bbe\u7f6e\u7684\u67d0\u4e9b\u9501\u5b9a\u53ef\u80fd\u4f1a\u4fdd\u7559;(\u5982\u679cSELECT\u8bed\u53e5\u5728\u4e8b\u52a1\u4e2d\u8c03\u7528\u4e00\u4e2a\u5b58\u50a8\u51fd\u6570,\u800c\u8be5\u51fd\u6570\u4e2d\u7684\u4e00\u4e2a\u8bed\u53e5\u51fa\u73b0\u9519\u8bef,\u5219\u8be5\u8bed\u53e5\u5c06\u56de\u6eda;\u540c\u65f6,\u5982\u679c\u6b64\u540e\u6267\u884cROLLBACK,\u5219\u6574\u4e2a\u4e8b\u52a1\u5c06\u56de\u6eda)<\/div>\n
\u00a0 \u00a0 3.\u53d1\u751f\u6b64\u95ee\u9898\u7684\u539f\u56e0\u662f,InnoDB\u5b58\u50a8\u884c\u9501\u7684\u683c\u5f0f\u4f7f\u5b83\u6b64\u540e\u65e0\u6cd5\u8bc6\u522b\u9501\u548c\u8bed\u53e5\u4e4b\u95f4\u7684\u5bf9\u5e94\u5173\u7cfb;<\/div>\n
<\/div>\n
—\u00a0\u4e8b\u52a1\u793a\u4f8b:\u6b7b\u9501;<\/div>\n
s1>\u00a0CREATE\u00a0TABLE\u00a0t_dl1(id\u00a0INT);<\/div>\n
s1>\u00a0CREATE\u00a0TABLE\u00a0t_dl2(id\u00a0INT);<\/div>\n
s1>\u00a0INSERT\u00a0INTO\u00a0t_dl1\u00a0VALUES(1);<\/div>\n
s1>\u00a0INSERT\u00a0INTO\u00a0t_dl2\u00a0VALUES(1);<\/div>\n
s1>\u00a0COMMIT;<\/div>\n
<\/div>\n
mysql>\u00a0PROMPT\u00a0s1><\/div>\n
s1>\u00a0START\u00a0TRANSACTION;<\/div>\n
s1>\u00a0UPDATE\u00a0t_dl1\u00a0SET\u00a0id\u00a0=\u00a01\u00a0WHERE\u00a0id\u00a0=\u00a01;<\/div>\n
<\/div>\n
mysql>\u00a0PROMPT\u00a0s2><\/div>\n
s1>\u00a0START\u00a0TRANSACTION;<\/div>\n
s1>\u00a0UPDATE\u00a0t_dl2\u00a0SET\u00a0id\u00a0=\u00a01\u00a0WHERE\u00a0id\u00a0=\u00a01;<\/div>\n
<\/div>\n
s1>\u00a0UPDATE\u00a0t_dl2\u00a0SET\u00a0id\u00a0=\u00a01\u00a0WHERE\u00a0id\u00a0=\u00a01;<\/div>\n
<\/div>\n
s2>\u00a0UPDATE\u00a0t_dl1\u00a0SET\u00a0id\u00a0=\u00a01\u00a0WHERE\u00a0id\u00a0=\u00a01;<\/div>\n
ERROR\u00a01213\u00a0(40001):\u00a0Deadlock\u00a0found\u00a0when\u00a0trying\u00a0to\u00a0get\u00a0lock;\u00a0try\u00a0restarting\u00a0transaction<\/div>\n
<\/div>\n
—\u00a0\u9690\u5f0f\u9501;<\/div>\n
1.InnoDB\u8868\u4f1a\u4f7f\u7528\u884c\u7ea7\u522b\u9501\u5b9a,\u4ee5\u6ee1\u8db3\u6700\u9ad8\u53ef\u80fd\u7684\u5e76\u53d1;<\/div>\n
2.\u5bf9\u4e8eInnoDB\u5b58\u50a8\u5f15\u64ce,\u8bf7\u907f\u514d\u4f7f\u7528LOCK\u00a0TABLES\u8bed\u53e5;\u5b83\u4e0d\u4f1a\u63d0\u4f9b\u4efb\u4f55\u989d\u5916\u7684\u4fdd\u62a4,\u5374\u4f1a\u51cf\u5c11\u5e76\u53d1\u6027;\u5229\u7528\u81ea\u52a8\u884c\u7ea7\u522b\u9501\u5b9a,\u9700\u5bf9\u8868\u8fdb\u884c\u9501\u5b9a\u548c\u89e3\u9501;<\/div>\n
<\/div>\n
—\u00a0\u8bfe\u540e\u7ec3\u4e60;<\/div>\n
<\/div>\n","protected":false},"excerpt":{"rendered":"

—\u00a0\u4e8b\u52a1; \u5728MySQL\u4e2d,\u53ea\u6709\u90a3\u4e9b\u4f7f\u7528\u4e8b\u52a1\u5b58\u50a8\u5f15\u64ce(\u5982InnoDB)\u7684\u8868\u624d\u652f\u6301\u4e8b\u52a1;\u8fd9\u4e9b\u8bed\u53e5\u4e0d\u4f1a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21],"tags":[27,31],"class_list":["post-1301","post","type-post","status-publish","format-standard","hentry","category-mysql","tag-mysql","tag-mysql_ocp"],"_links":{"self":[{"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=\/wp\/v2\/posts\/1301","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1301"}],"version-history":[{"count":1,"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=\/wp\/v2\/posts\/1301\/revisions"}],"predecessor-version":[{"id":1302,"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=\/wp\/v2\/posts\/1301\/revisions\/1302"}],"wp:attachment":[{"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1301"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.royalwzy.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}