{"id":1684,"date":"2022-11-24T17:48:42","date_gmt":"2022-11-24T09:48:42","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1684"},"modified":"2022-11-27T12:40:57","modified_gmt":"2022-11-27T04:40:57","slug":"1684","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1684","title":{"rendered":"\u9501\u7684\u6982\u8ff0_\u8bfb\u5199\u7684\u5e76\u53d1\u95ee\u9898\u3001\u6570\u636e\u64cd\u4f5c\u7c7b\u578b\u7684\u89d2\u5ea6\u7406\u89e3S\u9501\u4e0eX\u9501\u3001\u8868\u9501\u4e4bS\u9501\u3001X\u9501\u3001\u610f\u5411\u9501\u3001\u8868\u9501\u4e4b\u81ea\u589e\u9501\u3001\u5143\u6570\u636e\u9501\u3001\u884c\u9501\u4e4b\u8bb0\u5f55\u9501\u3001\u95f4\u9699\u9501\u3001\u884c\u9501\u4e4b\u4e34\u952e\u9501\u4e0e\u63d2\u5165\u610f\u5411\u9501\u3001\u9875\u9501\u7684\u7406\u89e3\u3001\u4e50\u89c2\u9501\u4e0e\u60b2\u89c2\u9501\u7684\u4f7f\u7528\u3001\u52a0\u9501\u65b9\u5f0f\u5212\u5206\uff1a\u9690\u5f0f\u9501\u4e0e\u663e\u5f0f\u9501\u3001\u5168\u5c40\u9501\u4e0e\u6b7b\u9501\u7684\u7406\u89e3\u3001\u9501\u7684\u5185\u5b58\u7ed3\u6784\u4e0e\u76d1\u63a7\u7b56\u7565"},"content":{"rendered":"\n
# \u7b2c15\u7ae0_\u9501\n\n# \u4e8b\u52a1\u7684 \u9694\u79bb\u6027 \u7531\u8fd9\u7ae0\u8bb2\u8ff0\u7684 \u9501 \u6765\u5b9e\u73b0\u3002\n\n# 1. \u6982\u8ff0\n\n# \u5728\u6570\u636e\u5e93\u4e2d\uff0c\u9664\u4f20\u7edf\u7684\u8ba1\u7b97\u8d44\u6e90\uff08\u5982CPU\u3001RAM\u3001I\/O\u7b49\uff09\u7684\u4e89\u7528\u4ee5\u5916\uff0c\u6570\u636e\u4e5f\u662f\u4e00\u79cd\u4f9b\u8bb8\u591a\u7528\u6237\u5171\u4eab\u7684\u8d44\u6e90\u3002\n# \u4e3a\u4fdd\u8bc1\u6570\u636e\u7684\u4e00\u81f4\u6027\uff0c\u9700\u8981\u5bf9 \u5e76\u53d1\u64cd\u4f5c\u8fdb\u884c\u63a7\u5236 \uff0c\u56e0\u6b64\u4ea7\u751f\u4e86 \u9501 \u3002\n# \u540c\u65f6 \u9501\u673a\u5236 \u4e5f\u4e3a\u5b9e\u73b0MySQL\u7684\u5404\u4e2a\u9694\u79bb\u7ea7\u522b\u63d0\u4f9b\u4e86\u4fdd\u8bc1\u3002 \u9501\u51b2\u7a81 \u4e5f\u662f\u5f71\u54cd\u6570\u636e\u5e93 \u5e76\u53d1\u8bbf\u95ee\u6027\u80fd \u7684\u4e00\u4e2a\u91cd\u8981\u56e0\u7d20\u3002\n# \u6240\u4ee5\u9501\u5bf9\u6570\u636e\u5e93\u800c\u8a00\u663e\u5f97\u5c24\u5176\u91cd\u8981\uff0c\u4e5f\u66f4\u52a0\u590d\u6742\u3002\n\n# 2. MySQL\u5e76\u53d1\u4e8b\u52a1\u8bbf\u95ee\u76f8\u540c\u8bb0\u5f55\n\n# \u5e76\u53d1\u4e8b\u52a1\u8bbf\u95ee\u76f8\u540c\u8bb0\u5f55\u7684\u60c5\u51b5\u5927\u81f4\u53ef\u4ee5\u5212\u5206\u4e3a3\u79cd\uff1a\n\n# 2.1 \u8bfb-\u8bfb\u60c5\u51b5\n# \u8bfb-\u8bfb \u60c5\u51b5\uff0c\u5373\u5e76\u53d1\u4e8b\u52a1\u76f8\u7ee7 \u8bfb\u53d6\u76f8\u540c\u7684\u8bb0\u5f55 \u3002\u8bfb\u53d6\u64cd\u4f5c\u672c\u8eab\u4e0d\u4f1a\u5bf9\u8bb0\u5f55\u6709\u4efb\u4f55\u5f71\u54cd\uff0c\n# \u5e76\u4e0d\u4f1a\u5f15\u8d77\u4ec0\u4e48\u95ee\u9898\uff0c\u6240\u4ee5\u5141\u8bb8\u8fd9\u79cd\u60c5\u51b5\u7684\u53d1\u751f\u3002\n\n# 2.2 \u5199-\u5199\u60c5\u51b5\n# \u5199-\u5199 \u60c5\u51b5\uff0c\u5373\u5e76\u53d1\u4e8b\u52a1\u76f8\u7ee7\u5bf9\u76f8\u540c\u7684\u8bb0\u5f55\u505a\u51fa\u6539\u52a8\u3002\n\n# \u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u4f1a\u53d1\u751f \u810f\u5199 \u7684\u95ee\u9898\uff0c\u4efb\u4f55\u4e00\u79cd\u9694\u79bb\u7ea7\u522b\u90fd\u4e0d\u5141\u8bb8\u8fd9\u79cd\u95ee\u9898\u7684\u53d1\u751f\u3002\n# \u6240\u4ee5\u5728\u591a\u4e2a\u672a\u63d0\u4ea4\u4e8b\u52a1\u76f8\u7ee7\u5bf9\u4e00\u6761\u8bb0\u5f55\u505a\u6539\u52a8\u65f6\uff0c\u9700\u8981\u8ba9\u5b83\u4eec \u6392\u961f\u6267\u884c \uff0c\u8fd9\u4e2a\u6392\u961f\u7684\u8fc7\u7a0b\u5176\u5b9e\u662f\u901a\u8fc7 \u9501 \u6765\u5b9e\u73b0\u7684\u3002\n# \u8fd9\u4e2a\u6240\u8c13\u7684\u9501\u5176\u5b9e\u662f\u4e00\u4e2a \u5185\u5b58\u4e2d\u7684\u7ed3\u6784 \uff0c\u5728\u4e8b\u52a1\u6267\u884c\u524d\u672c\u6765\u662f\u6ca1\u6709\u9501\u7684\uff0c\n# \u4e5f\u5c31\u662f\u8bf4\u4e00\u5f00\u59cb\u662f\u6ca1\u6709 \u9501\u7ed3\u6784 \u548c\u8bb0\u5f55\u8fdb\u884c\u5173\u8054\u7684\n\n# \u5c0f\u7ed3\u51e0\u79cd\u8bf4\u6cd5\uff1a\n# \u4e0d\u52a0\u9501\n#     \u610f\u601d\u5c31\u662f\u4e0d\u9700\u8981\u5728\u5185\u5b58\u4e2d\u751f\u6210\u5bf9\u5e94\u7684 \u9501\u7ed3\u6784 \uff0c\u53ef\u4ee5\u76f4\u63a5\u6267\u884c\u64cd\u4f5c\u3002\n\n# \u83b7\u53d6\u9501\u6210\u529f\uff0c\u6216\u8005\u52a0\u9501\u6210\u529f\n#     \u610f\u601d\u5c31\u662f\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e86\u5bf9\u5e94\u7684 \u9501\u7ed3\u6784 \uff0c\u800c\u4e14\u9501\u7ed3\u6784\u7684 is_waiting \u5c5e\u6027\u4e3a false \uff0c\n# \u4e5f\u5c31\u662f\u4e8b\u52a1\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u64cd\u4f5c\u3002\n\n# \u83b7\u53d6\u9501\u5931\u8d25\uff0c\u6216\u8005\u52a0\u9501\u5931\u8d25\uff0c\u6216\u8005\u6ca1\u6709\u83b7\u53d6\u5230\u9501\n#     \u610f\u601d\u5c31\u662f\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e86\u5bf9\u5e94\u7684 \u9501\u7ed3\u6784 \uff0c\u4e0d\u8fc7\u9501\u7ed3\u6784\u7684 is_waiting \u5c5e\u6027\u4e3a true \uff0c\n# \u4e5f\u5c31\u662f\u4e8b\u52a1\u9700\u8981\u7b49\u5f85\uff0c\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u64cd\u4f5c\u3002\n\n# 2.3 \u8bfb-\u5199\u6216\u5199-\u8bfb\u60c5\u51b5\n# \u8bfb-\u5199 \u6216 \u5199-\u8bfb \uff0c\u5373\u4e00\u4e2a\u4e8b\u52a1\u8fdb\u884c\u8bfb\u53d6\u64cd\u4f5c\uff0c\u53e6\u4e00\u4e2a\u8fdb\u884c\u6539\u52a8\u64cd\u4f5c\u3002\n# \u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ef\u80fd\u53d1\u751f \u810f\u8bfb \u3001 \u4e0d\u53ef\u91cd\u590d\u8bfb \u3001 \u5e7b\u8bfb \u7684\u95ee\u9898\u3002\n\n# \u5404\u4e2a\u6570\u636e\u5e93\u5382\u5546\u5bf9 SQL\u6807\u51c6 \u7684\u652f\u6301\u90fd\u53ef\u80fd\u4e0d\u4e00\u6837\u3002\n# \u6bd4\u5982MySQL\u5728 REPEATABLE READ \u9694\u79bb\u7ea7\u522b\u4e0a\u5c31\u5df2\u7ecf\u89e3\u51b3\u4e86 \u5e7b\u8bfb \u95ee\u9898\u3002\n\n# 2.4 \u5e76\u53d1\u95ee\u9898\u7684\u89e3\u51b3\u65b9\u6848\n# \u600e\u4e48\u89e3\u51b3 \u810f\u8bfb \u3001 \u4e0d\u53ef\u91cd\u590d\u8bfb \u3001 \u5e7b\u8bfb \u8fd9\u4e9b\u95ee\u9898\u5462\uff1f\u5176\u5b9e\u6709\u4e24\u79cd\u53ef\u9009\u7684\u89e3\u51b3\u65b9\u6848\uff1a\n\n# \u65b9\u6848\u4e00\uff1a\u8bfb\u64cd\u4f5c\u5229\u7528\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\uff08 MVCC \uff0c\u4e0b\u7ae0\u8bb2\u89e3\uff09\uff0c\u5199\u64cd\u4f5c\u8fdb\u884c \u52a0\u9501 \u3002\n\n# \u666e\u901a\u7684SELECT\u8bed\u53e5\u5728READ COMMITTED\u548cREPEATABLE READ\u9694\u79bb\u7ea7\u522b\u4e0b\u4f1a\u4f7f\u7528\u5230MVCC\u8bfb\u53d6\u8bb0\u5f55\u3002\n#     \u5728 READ COMMITTED \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u4e00\u4e2a\u4e8b\u52a1\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\u6bcf\u6b21\u6267\u884cSELECT\u64cd\u4f5c\u65f6\u90fd\u4f1a\u751f\u6210\u4e00\u4e2aReadView\uff0c\n# ReadView\u7684\u5b58\u5728\u672c\u8eab\u5c31\u4fdd\u8bc1\u4e86 \u4e8b\u52a1\u4e0d\u53ef\u4ee5\u8bfb\u53d6\u5230\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539 \uff0c\u4e5f\u5c31\u662f\u907f\u514d\u4e86\u810f\u8bfb\u73b0\u8c61\uff1b\n#     \u5728 REPEATABLE READ \u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u4e00\u4e2a\u4e8b\u52a1\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\u53ea\u6709 \u7b2c\u4e00\u6b21\u6267\u884cSELECT\u64cd\u4f5c \u624d\u4f1a\u751f\u6210\u4e00\u4e2aReadView\uff0c\n# \u4e4b\u540e\u7684SELECT\u64cd\u4f5c\u90fd \u590d\u7528 \u8fd9\u4e2aReadView\uff0c\u8fd9\u6837\u4e5f\u5c31\u907f\u514d\u4e86\u4e0d\u53ef\u91cd\u590d\u8bfb\u548c\u5e7b\u8bfb\u7684\u95ee\u9898\u3002\n\n# \u65b9\u6848\u4e8c\uff1a\u8bfb\u3001\u5199\u64cd\u4f5c\u90fd\u91c7\u7528 \u52a0\u9501 \u7684\u65b9\u5f0f\u3002\n\n# \u5c0f\u7ed3\u5bf9\u6bd4\u53d1\u73b0\uff1a\n#     \u91c7\u7528 MVCC \u65b9\u5f0f\u7684\u8bdd\uff0c \u8bfb-\u5199 \u64cd\u4f5c\u5f7c\u6b64\u5e76\u4e0d\u51b2\u7a81\uff0c \u6027\u80fd\u66f4\u9ad8 \u3002\n#     \u91c7\u7528 \u52a0\u9501 \u65b9\u5f0f\u7684\u8bdd\uff0c \u8bfb-\u5199 \u64cd\u4f5c\u5f7c\u6b64\u9700\u8981 \u6392\u961f\u6267\u884c \uff0c\u5f71\u54cd\u6027\u80fd\u3002\n# \u4e00\u822c\u60c5\u51b5\u4e0b\u6211\u4eec\u5f53\u7136\u613f\u610f\u91c7\u7528 MVCC \u6765\u89e3\u51b3 \u8bfb-\u5199 \u64cd\u4f5c\u5e76\u53d1\u6267\u884c\u7684\u95ee\u9898\uff0c\u4f46\u662f\u4e1a\u52a1\u5728\u67d0\u4e9b\u7279\u6b8a\u60c5\u51b5\u4e0b\uff0c\n# \u8981\u6c42\u5fc5\u987b\u91c7\u7528 \u52a0\u9501 \u7684\u65b9\u5f0f\u6267\u884c\u3002\n\n# 3. \u9501\u7684\u4e0d\u540c\u89d2\u5ea6\u5206\u7c7b\n\n# 3.1 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c7b\u578b\u5212\u5206\uff1a\u8bfb\u9501\u3001\u5199\u9501\n\n# \u8bfb\u9501 \uff1a\u4e5f\u79f0\u4e3a \u5171\u4eab\u9501 \u3001\u82f1\u6587\u7528 S \u8868\u793a\u3002\u9488\u5bf9\u540c\u4e00\u4efd\u6570\u636e\uff0c\u591a\u4e2a\u4e8b\u52a1\u7684\u8bfb\u64cd\u4f5c\u53ef\u4ee5\u540c\u65f6\u8fdb\u884c\u800c\u4e0d\u4f1a\u4e92\u76f8\u5f71\u54cd\uff0c\n# \u76f8\u4e92\u4e0d\u963b\u585e\u7684\u3002\n\n# \u5199\u9501 \uff1a\u4e5f\u79f0\u4e3a \u6392\u4ed6\u9501 \u3001\u82f1\u6587\u7528 X \u8868\u793a\u3002\u5f53\u524d\u5199\u64cd\u4f5c\u6ca1\u6709\u5b8c\u6210\u524d\uff0c\u5b83\u4f1a\u963b\u65ad\u5176\u4ed6\u5199\u9501\u548c\u8bfb\u9501\u3002\n# \u8fd9\u6837\u5c31\u80fd\u786e\u4fdd\u5728\u7ed9\u5b9a\u7684\u65f6\u95f4\u91cc\uff0c\u53ea\u6709\u4e00\u4e2a\u4e8b\u52a1\u80fd\u6267\u884c\u5199\u5165\uff0c\u5e76\u9632\u6b62\u5176\u4ed6\u7528\u6237\u8bfb\u53d6\u6b63\u5728\u5199\u5165\u7684\u540c\u4e00\u8d44\u6e90\u3002\n\n# \u9700\u8981\u6ce8\u610f\u7684\u662f\u5bf9\u4e8e InnoDB \u5f15\u64ce\u6765\u8bf4\uff0c\u8bfb\u9501\u548c\u5199\u9501\u53ef\u4ee5\u52a0\u5728\u8868\u4e0a\uff0c\u4e5f\u53ef\u4ee5\u52a0\u5728\u884c\u4e0a\u3002\n\n# 1. \u8bfb\u64cd\u4f5c\n\nUSE atguigudb3;\n\nSHOW TABLES;\n\nSELECT * FROM account;\n\nBEGIN;\n\n#\u5171\u4eab\u9501 s\u9501\nSELECT * FROM account LOCK IN SHARE MODE;\n\nCOMMIT;\n\nBEGIN;\n\n#\u6392\u4ed6\u9501 x\u9501\nSELECT * FROM account FOR UPDATE;   #\u963b\u585e\n\nCOMMIT;\n\nBEGIN;\n\n#\u6392\u4ed6\u9501 x\u9501\nSELECT * FROM account FOR UPDATE;\n\nCOMMIT;\n\n#\u901a\u8fc7\u6dfb\u52a0NOWAIT\u3001SKIP LOCKED\u8bed\u6cd5\uff0c\u80fd\u591f\u7acb\u5373\u8fd4\u56de\u3002\u5982\u679c\u67e5\u8be2\u7684\u884c\u5df2\u7ecf\u52a0\u9501\uff1a\n#\u90a3\u4e48NOWAIT\u4f1a\u7acb\u5373\u62a5\u9519\u8fd4\u56de\nSELECT * FROM account FOR UPDATE NOWAIT;\n#\u800cSKIP LOCKED\u4e5f\u4f1a\u7acb\u5373\u8fd4\u56de\uff0c\u53ea\u662f\u8fd4\u56de\u7684\u7ed3\u679c\u4e2d\u4e0d\u5305\u542b\u88ab\u9501\u5b9a\u7684\u884c\u3002\nSELECT * FROM account FOR UPDATE SKIP LOCKED;\n\n# 2. \u5199\u64cd\u4f5c\n\n# 3.2 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\uff1a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u3001\u884c\u9501\n\n# 1. \u8868\u9501\uff08Table Lock\uff09\n\n# \u2460 \u8868\u7ea7\u522b\u7684S\u9501\u3001X\u9501\n\n# \u5728\u5bf9\u67d0\u4e2a\u8868\u6267\u884cSELECT\u3001INSERT\u3001DELETE\u3001UPDATE\u8bed\u53e5\u65f6\uff0c\n# InnoDB\u5b58\u50a8\u5f15\u64ce\u662f\u4e0d\u4f1a\u4e3a\u8fd9\u4e2a\u8868\u6dfb\u52a0\u8868\u7ea7\u522b\u7684 S\u9501 \u6216\u8005 X\u9501 \u7684\u3002\n# \u5728\u5bf9\u67d0\u4e2a\u8868\u6267\u884c\u4e00\u4e9b\u8bf8\u5982 ALTER TABLE \u3001 DROP TABLE \u8fd9\u7c7b\u7684 DDL \u8bed\u53e5\u65f6\uff0c\n# \u5176\u4ed6\u4e8b\u52a1\u5bf9\u8fd9\u4e2a\u8868\u5e76\u53d1\u6267\u884c\u8bf8\u5982SELECT\u3001INSERT\u3001DELETE\u3001UPDATE\u7684\u8bed\u53e5\u4f1a\u53d1\u751f\u963b\u585e\u3002\n# \u540c\u7406\uff0c\u67d0\u4e2a\u4e8b\u52a1\u4e2d\u5bf9\u67d0\u4e2a\u8868\u6267\u884cSELECT\u3001INSERT\u3001DELETE\u3001UPDATE\u8bed\u53e5\u65f6\uff0c\n# \u5728\u5176\u4ed6\u4f1a\u8bdd\u4e2d\u5bf9\u8fd9\u4e2a\u8868\u6267\u884c DDL \u8bed\u53e5\u4e5f\u4f1a\u53d1\u751f\u963b\u585e\u3002\n# \u8fd9\u4e2a\u8fc7\u7a0b\u5176\u5b9e\u662f\u901a\u8fc7\u5728 server\u5c42 \u4f7f\u7528\u4e00\u79cd\u79f0\u4e4b\u4e3a \u5143\u6570\u636e\u9501 \uff08\u82f1\u6587\u540d\uff1a Metadata Locks \uff0c\u7b80\u79f0 MDL \uff09\u7ed3\u6784\u6765\u5b9e\u73b0\u7684\u3002\n\n# \u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u4e0d\u4f1a\u4f7f\u7528InnoDB\u5b58\u50a8\u5f15\u64ce\u63d0\u4f9b\u7684\u8868\u7ea7\u522b\u7684 S\u9501 \u548c X\u9501 \u3002\u53ea\u4f1a\u5728\u4e00\u4e9b\u7279\u6b8a\u60c5\u51b5\u4e0b\uff0c\n# \u6bd4\u65b9\u8bf4 \u5d29\u6e83\u6062\u590d \u8fc7\u7a0b\u4e2d\u7528\u5230\u3002\u6bd4\u5982\uff0c\u5728\u7cfb\u7edf\u53d8\u91cf autocommit=0\uff0cinnodb_table_locks = 1 \u65f6\uff0c\n# \u624b\u52a8 \u83b7\u53d6InnoDB\u5b58\u50a8\u5f15\u64ce\u63d0\u4f9b\u7684\u8868t \u7684 S\u9501 \u6216\u8005 X\u9501 \u53ef\u4ee5\u8fd9\u4e48\u5199\uff1a\n#     LOCK TABLES t READ \uff1aInnoDB\u5b58\u50a8\u5f15\u64ce\u4f1a\u5bf9\u8868 t \u52a0\u8868\u7ea7\u522b\u7684 S\u9501 \u3002\n#     LOCK TABLES t WRITE \uff1aInnoDB\u5b58\u50a8\u5f15\u64ce\u4f1a\u5bf9\u8868 t \u52a0\u8868\u7ea7\u522b\u7684 X\u9501 \u3002\n\n# \u4e0d\u8fc7\u5c3d\u91cf\u907f\u514d\u5728\u4f7f\u7528InnoDB\u5b58\u50a8\u5f15\u64ce\u7684\u8868\u4e0a\u4f7f\u7528 LOCK TABLES \u8fd9\u6837\u7684\u624b\u52a8\u9501\u8868\u8bed\u53e5\uff0c\n# \u5b83\u4eec\u5e76\u4e0d\u4f1a\u63d0\u4f9b\u4ec0\u4e48\u989d\u5916\u7684\u4fdd\u62a4\uff0c\u53ea\u662f\u4f1a\u964d\u4f4e\u5e76\u53d1\u80fd\u529b\u800c\u5df2\u3002InnoDB\u7684\u5389\u5bb3\u4e4b\u5904\u8fd8\u662f\u5b9e\u73b0\u4e86\u66f4\u7ec6\u7c92\u5ea6\u7684 \u884c\u9501 \uff0c\n# \u5173\u4e8eInnoDB\u8868\u7ea7\u522b\u7684 S\u9501 \u548c X\u9501 \u5927\u5bb6\u4e86\u89e3\u4e00\u4e0b\u5c31\u53ef\u4ee5\u4e86\u3002\n\n#\u4e3e\u4f8b\uff1aMyISAM\u5f15\u64ce\u4e0b\u7684\u8868\u9501\u3002\n\n# \u6b65\u9aa41\uff1a\u521b\u5efa\u8868\u5e76\u6dfb\u52a0\u6570\u636e\nCREATE TABLE mylock(\n    id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,\n    name VARCHAR(20)\n)ENGINE MyISAM;\n\nINSERT INTO mylock(name) VALUES ('a');\n\nSELECT * FROM mylock;\n\n# \u6b65\u9aa42\uff1a\u67e5\u770b\u8868\u4e0a\u52a0\u8fc7\u7684\u9501\nSHOW OPEN TABLES;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\n# \u6b65\u9aa43\uff1a\u624b\u52a8\u589e\u52a0\u8868\u9501\u547d\u4ee4\uff1as\u9501\nLOCK TABLES mylock READ;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\n# \u6b65\u9aa44\uff1a\u91ca\u653e\u8868\u9501\nUNLOCK TABLES;\n\n# \u624b\u52a8\u589e\u52a0\u8868\u9501\u547d\u4ee4\uff1ax\u9501\nLOCK TABLES mylock WRITE;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\nUNLOCK TABLES;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\n# MySQL\u7684\u8868\u7ea7\u9501\u6709\u4e24\u79cd\u6a21\u5f0f\uff1a\uff08\u4ee5MyISAM\u8868\u8fdb\u884c\u64cd\u4f5c\u7684\u6f14\u793a\uff09\n#     \u8868\u5171\u4eab\u8bfb\u9501\uff08Table Read Lock\uff09\n#     \u8868\u72ec\u5360\u5199\u9501\uff08Table Write Lock\uff09\n\n# \u9501\u7c7b\u578b     \u81ea\u5df1\u53ef\u8bfb    \u81ea\u5df1\u53ef\u5199    \u81ea\u5df1\u53ef\u64cd\u4f5c\u5176\u4ed6\u8868    \u4ed6\u4eba\u53ef\u8bfb    \u4ed6\u4eba\u53ef\u5199\n# \u8bfb\u9501       \u662f          \u5426          \u5426                 \u662f          \u5426\uff0c\u7b49\n# \u5199\u9501       \u662f          \u662f          \u5426                 \u5426\uff0c\u7b49      \u5426\uff0c\u7b49\n\nBEGIN;\n\nLOCK TABLES mylock READ;\n\nSELECT * FROM mylock;\n\nUPDATE mylock SET name = 'a1'\nWHERE id = 1;\n\nSELECT * FROM account;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\nUNLOCK TABLES;\n\nLOCK TABLES mylock WRITE;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\nSELECT * FROM mylock;\n\nUPDATE mylock SET name = 'a3'\nWHERE id = 1;\n\nSELECT * FROM account;\n\nUNLOCK TABLES;\n\nSHOW OPEN TABLES WHERE In_use > 0;\n\n# \u2461 \u610f\u5411\u9501 \uff08intention lock\uff09\n\n# InnoDB \u652f\u6301 \u591a\u7c92\u5ea6\u9501\uff08multiple granularity locking\uff09 \uff0c\u5b83\u5141\u8bb8 \u884c\u7ea7\u9501 \u4e0e \u8868\u7ea7\u9501 \u5171\u5b58\uff0c\n# \u800c\u610f\u5411\u9501\u5c31\u662f\u5176\u4e2d\u7684\u4e00\u79cd \u8868\u9501 \u3002\n\n# \u610f\u5411\u9501\u5206\u4e3a\u4e24\u79cd\uff1a\n\n# \u610f\u5411\u5171\u4eab\u9501\uff08intention shared lock, IS\uff09\uff1a\u4e8b\u52a1\u6709\u610f\u5411\u5bf9\u8868\u4e2d\u7684\u67d0\u4e9b\u884c\u52a0\u5171\u4eab\u9501\uff08S\u9501\uff09\n-- \u4e8b\u52a1\u8981\u83b7\u53d6\u67d0\u4e9b\u884c\u7684 S \u9501\uff0c\u5fc5\u987b\u5148\u83b7\u5f97\u8868\u7684 IS \u9501\u3002\n# SELECT column FROM table ... LOCK IN SHARE MODE;\n\n# \u610f\u5411\u6392\u4ed6\u9501\uff08intention exclusive lock, IX\uff09\uff1a\u4e8b\u52a1\u6709\u610f\u5411\u5bf9\u8868\u4e2d\u7684\u67d0\u4e9b\u884c\u52a0\u6392\u4ed6\u9501\uff08X\u9501\uff09\n-- \u4e8b\u52a1\u8981\u83b7\u53d6\u67d0\u4e9b\u884c\u7684 X \u9501\uff0c\u5fc5\u987b\u5148\u83b7\u5f97\u8868\u7684 IX \u9501\u3002\n# SELECT column FROM table ... FOR UPDATE;\n\n# \u5373\uff1a\u610f\u5411\u9501\u662f\u7531\u5b58\u50a8\u5f15\u64ce \u81ea\u5df1\u7ef4\u62a4\u7684 \uff0c\u7528\u6237\u65e0\u6cd5\u624b\u52a8\u64cd\u4f5c\u610f\u5411\u9501\uff0c\u5728\u4e3a\u6570\u636e\u884c\u52a0\u5171\u4eab \/ \u6392\u4ed6\u9501\u4e4b\u524d\uff0c\n# InooDB \u4f1a\u5148\u83b7\u53d6\u8be5\u6570\u636e\u884c \u6240\u5728\u6570\u636e\u8868\u7684\u5bf9\u5e94\u610f\u5411\u9501 \u3002\n\nCREATE TABLE teacher(\n    id INT NOT NULL,\n    name VARCHAR(255) NOT NULL,\n    PRIMARY KEY(id)\n)ENGINE=INNODB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;\n\nINSERT INTO teacher\nVALUES('1','zhangsan'),\n       ('2','lisi'),\n       ('3','wangwu'),\n       ('4','zhaoliu'),\n       ('5','songhongkang'),\n       ('6','leifengyang');\n\nSELECT * FROM teacher;\n\nSELECT @@transaction_isolation;\n\nBEGIN;\n\nSELECT * FROM teacher\nWHERE id = 6 FOR UPDATE;\n\nCOMMIT;\n\n# \u610f\u5411\u9501\u7684\u5e76\u53d1\u6027\n# \u610f\u5411\u9501\u4e0d\u4f1a\u4e0e\u884c\u7ea7\u7684\u5171\u4eab \/ \u6392\u4ed6\u9501\u4e92\u65a5\uff01\u6b63\u56e0\u4e3a\u5982\u6b64\uff0c\n# \u610f\u5411\u9501\u5e76\u4e0d\u4f1a\u5f71\u54cd\u5230\u591a\u4e2a\u4e8b\u52a1\u5bf9\u4e0d\u540c\u6570\u636e\u884c\u52a0\u6392\u4ed6\u9501\u65f6\u7684\u5e76\u53d1\u6027\u3002\uff08\u4e0d\u7136\u6211\u4eec\u76f4\u63a5\u7528\u666e\u901a\u7684\u8868\u9501\u5c31\u884c\u4e86\uff09\n\nBEGIN;\n\nSELECT * FROM teacher\nWHERE id = 6 FOR UPDATE;\n\nCOMMIT;\n\n# \u6211\u4eec\u6269\u5c55\u4e00\u4e0b\u4e0a\u9762 teacher\u8868\u7684\u4f8b\u5b50\u6765\u6982\u62ec\u4e00\u4e0b\u610f\u5411\u9501\u7684\u4f5c\u7528\uff08\u4e00\u6761\u6570\u636e\u4ece\u88ab\u9501\u5b9a\u5230\u88ab\u91ca\u653e\u7684\u8fc7\u7a0b\u4e2d\uff0c\n# \u53ef\u80fd\u5b58\u5728\u591a\u79cd\u4e0d\u540c\u9501\uff0c\u4f46\u662f\u8fd9\u91cc\u6211\u4eec\u53ea\u7740\u91cd\u8868\u73b0\u610f\u5411\u9501\uff09\u3002\n\n# \u4ece\u4e0a\u9762\u7684\u6848\u4f8b\u53ef\u4ee5\u5f97\u5230\u5982\u4e0b\u7ed3\u8bba\uff1a\n# 1. InnoDB \u652f\u6301 \u591a\u7c92\u5ea6\u9501 \uff0c\u7279\u5b9a\u573a\u666f\u4e0b\uff0c\u884c\u7ea7\u9501\u53ef\u4ee5\u4e0e\u8868\u7ea7\u9501\u5171\u5b58\u3002\n# 2. \u610f\u5411\u9501\u4e4b\u95f4\u4e92\u4e0d\u6392\u65a5\uff0c\u4f46\u9664\u4e86 IS \u4e0e S \u517c\u5bb9\u5916\uff0c \u610f\u5411\u9501\u4f1a\u4e0e \u5171\u4eab\u9501 \/ \u6392\u4ed6\u9501 \u4e92\u65a5 \u3002\n# 3. IX\uff0cIS\u662f\u8868\u7ea7\u9501\uff0c\u4e0d\u4f1a\u548c\u884c\u7ea7\u7684X\uff0cS\u9501\u53d1\u751f\u51b2\u7a81\u3002\u53ea\u4f1a\u548c\u8868\u7ea7\u7684X\uff0cS\u53d1\u751f\u51b2\u7a81\u3002\n# 4. \u610f\u5411\u9501\u5728\u4fdd\u8bc1\u5e76\u53d1\u6027\u7684\u524d\u63d0\u4e0b\uff0c\u5b9e\u73b0\u4e86 \u884c\u9501\u548c\u8868\u9501\u5171\u5b58 \u4e14 \u6ee1\u8db3\u4e8b\u52a1\u9694\u79bb\u6027 \u7684\u8981\u6c42\u3002\n\n# \u2462 \u81ea\u589e\u9501\uff08AUTO-INC\u9501\uff09\n\n# 1. \u201cSimple inserts\u201d \uff08\u7b80\u5355\u63d2\u5165\uff09\n# \u53ef\u4ee5 \u9884\u5148\u786e\u5b9a\u8981\u63d2\u5165\u7684\u884c\u6570 \uff08\u5f53\u8bed\u53e5\u88ab\u521d\u59cb\u5904\u7406\u65f6\uff09\u7684\u8bed\u53e5\u3002\n# \u5305\u62ec\u6ca1\u6709\u5d4c\u5957\u5b50\u67e5\u8be2\u7684\u5355\u884c\u548c\u591a\u884cINSERT...VALUES() \u548c REPLACE \u8bed\u53e5\u3002\u6bd4\u5982\u6211\u4eec\u4e0a\u9762\u4e3e\u7684\u4f8b\u5b50\u5c31\u5c5e\u4e8e\u8be5\u7c7b\u63d2\u5165\uff0c\n# \u5df2\u7ecf\u786e\u5b9a\u8981\u63d2\u5165\u7684\u884c\u6570\u3002\n\n# 2. \u201cBulk inserts\u201d \uff08\u6279\u91cf\u63d2\u5165\uff09\n# \u4e8b\u5148\u4e0d\u77e5\u9053\u8981\u63d2\u5165\u7684\u884c\u6570 \uff08\u548c\u6240\u9700\u81ea\u52a8\u9012\u589e\u503c\u7684\u6570\u91cf\uff09\u7684\u8bed\u53e5\u3002\u6bd4\u5982 INSERT ... SELECT \uff0c\n# REPLACE ... SELECT \u548c LOAD DATA \u8bed\u53e5\uff0c\u4f46\u4e0d\u5305\u62ec\u7eafINSERT\u3002 InnoDB\u5728\u6bcf\u5904\u7406\u4e00\u884c\uff0c\n# \u4e3aAUTO_INCREMENT\u5217\u5206\u914d\u4e00\u4e2a\u65b0\u503c\u3002\n\n# 3. \u201cMixed-mode inserts\u201d \uff08\u6df7\u5408\u6a21\u5f0f\u63d2\u5165\uff09\n# \u8fd9\u4e9b\u662f\u201cSimple inserts\u201d\u8bed\u53e5\u4f46\u662f\u6307\u5b9a\u90e8\u5206\u65b0\u884c\u7684\u81ea\u52a8\u9012\u589e\u503c\u3002\n# \u4f8b\u5982 INSERT INTO teacher (id,name) VALUES (1,'a'), (NULL,'b'), (5,'c'), (NULL,'d');\n# \u53ea\u662f\u6307\u5b9a\u4e86\u90e8\u5206id\u7684\u503c\u3002\u53e6\u4e00\u79cd\u7c7b\u578b\u7684\u201c\u6df7\u5408\u6a21\u5f0f\u63d2\u5165\u201d\u662f INSERT ... ON DUPLICATE KEY UPDATE \u3002\n\n# innodb_autoinc_lock_mode\u6709\u4e09\u79cd\u53d6\u503c\uff0c\u5206\u522b\u5bf9\u5e94\u4e0e\u4e0d\u540c\u9501\u5b9a\u6a21\u5f0f\uff1a\n\n# \uff081\uff09innodb_autoinc_lock_mode = 0(\u201c\u4f20\u7edf\u201d\u9501\u5b9a\u6a21\u5f0f)\n# \u5728\u6b64\u9501\u5b9a\u6a21\u5f0f\u4e0b\uff0c\u6240\u6709\u7c7b\u578b\u7684insert\u8bed\u53e5\u90fd\u4f1a\u83b7\u5f97\u4e00\u4e2a\u7279\u6b8a\u7684\u8868\u7ea7AUTO-INC\u9501\uff0c\u7528\u4e8e\u63d2\u5165\u5177\u6709AUTO_INCREMENT\u5217\u7684\u8868\u3002\n# \u8fd9\u79cd\u6a21\u5f0f\u5176\u5b9e\u5c31\u5982\u6211\u4eec\u4e0a\u9762\u7684\u4f8b\u5b50\uff0c\u5373\u6bcf\u5f53\u6267\u884cinsert\u7684\u65f6\u5019\uff0c\u90fd\u4f1a\u5f97\u5230\u4e00\u4e2a\u8868\u7ea7\u9501(AUTO-INC\u9501)\uff0c\n# \u4f7f\u5f97\u8bed\u53e5\u4e2d\u751f\u6210\u7684auto_increment\u4e3a\u987a\u5e8f\uff0c\u4e14\u5728binlog\u4e2d\u91cd\u653e\u7684\u65f6\u5019\uff0c\n# \u53ef\u4ee5\u4fdd\u8bc1master\u4e0eslave\u4e2d\u6570\u636e\u7684auto_increment\u662f\u76f8\u540c\u7684\u3002\u56e0\u4e3a\u662f\u8868\u7ea7\u9501\uff0c\n# \u5f53\u5728\u540c\u4e00\u65f6\u95f4\u591a\u4e2a\u4e8b\u52a1\u4e2d\u6267\u884cinsert\u7684\u65f6\u5019\uff0c\u5bf9\u4e8eAUTO-INC\u9501\u7684\u4e89\u593a\u4f1a \u9650\u5236\u5e76\u53d1 \u80fd\u529b\u3002\n\n# \uff082\uff09innodb_autoinc_lock_mode = 1(\u201c\u8fde\u7eed\u201d\u9501\u5b9a\u6a21\u5f0f)\n# \u5728 MySQL 8.0 \u4e4b\u524d\uff0c\u8fde\u7eed\u9501\u5b9a\u6a21\u5f0f\u662f \u9ed8\u8ba4 \u7684\u3002\n\n# \u5728\u8fd9\u4e2a\u6a21\u5f0f\u4e0b\uff0c\u201cbulk inserts\u201d\u4ecd\u7136\u4f7f\u7528AUTO-INC\u8868\u7ea7\u9501\uff0c\u5e76\u4fdd\u6301\u5230\u8bed\u53e5\u7ed3\u675f\u3002\n# \u8fd9\u9002\u7528\u4e8e\u6240\u6709INSERT ... SELECT\uff0cREPLACE ... SELECT\u548cLOAD DATA\u8bed\u53e5\u3002\n# \u540c\u4e00\u65f6\u523b\u53ea\u6709\u4e00\u4e2a\u8bed\u53e5\u53ef\u4ee5\u6301\u6709AUTO-INC\u9501\u3002\n\n# \u5bf9\u4e8e\u201cSimple inserts\u201d\uff08\u8981\u63d2\u5165\u7684\u884c\u6570\u4e8b\u5148\u5df2\u77e5\uff09\uff0c\n# \u5219\u901a\u8fc7\u5728 mutex\uff08\u8f7b\u91cf\u9501\uff09 \u7684\u63a7\u5236\u4e0b\u83b7\u5f97\u6240\u9700\u6570\u91cf\u7684\u81ea\u52a8\u9012\u589e\u503c\u6765\u907f\u514d\u8868\u7ea7AUTO-INC\u9501\uff0c\n# \u5b83\u53ea\u5728\u5206\u914d\u8fc7\u7a0b\u7684\u6301\u7eed\u65f6\u95f4\u5185\u4fdd\u6301\uff0c\u800c\u4e0d\u662f\u76f4\u5230\u8bed\u53e5\u5b8c\u6210\u3002\u4e0d\u4f7f\u7528\u8868\u7ea7AUTO-INC\u9501\uff0c\n# \u9664\u975eAUTO-INC\u9501\u7531\u53e6\u4e00\u4e2a\u4e8b\u52a1\u4fdd\u6301\u3002\u5982\u679c\u53e6\u4e00\u4e2a\u4e8b\u52a1\u4fdd\u6301AUTO-INC\u9501\uff0c\u5219\u201cSimpleinserts\u201d\u7b49\u5f85AUTO-INC\u9501\uff0c\n# \u5982\u540c\u5b83\u662f\u4e00\u4e2a\u201cbulk inserts\u201d\u3002\n\n# \uff083\uff09innodb_autoinc_lock_mode = 2(\u201c\u4ea4\u9519\u201d\u9501\u5b9a\u6a21\u5f0f)\n# \u4ece MySQL 8.0 \u5f00\u59cb\uff0c\u4ea4\u9519\u9501\u6a21\u5f0f\u662f \u9ed8\u8ba4 \u8bbe\u7f6e\u3002\n\n# \u5728\u6b64\u9501\u5b9a\u6a21\u5f0f\u4e0b\uff0c\u81ea\u52a8\u9012\u589e\u503c \u4fdd\u8bc1 \u5728\u6240\u6709\u5e76\u53d1\u6267\u884c\u7684\u6240\u6709\u7c7b\u578b\u7684insert\u8bed\u53e5\u4e2d\u662f \u552f\u4e00 \u4e14 \u5355\u8c03\u9012\u589e \u7684\u3002\n# \u4f46\u662f\uff0c\u7531\u4e8e\u591a\u4e2a\u8bed\u53e5\u53ef\u4ee5\u540c\u65f6\u751f\u6210\u6570\u5b57\uff08\u5373\uff0c\u8de8\u8bed\u53e5\u4ea4\u53c9\u7f16\u53f7\uff09\uff0c\u4e3a\u4efb\u4f55\u7ed9\u5b9a\u8bed\u53e5\u63d2\u5165\u7684\u884c\u751f\u6210\u7684\u503c\u53ef\u80fd\u4e0d\u662f\u8fde\u7eed\u7684\u3002\n\n# \u2463 \u5143\u6570\u636e\u9501\uff08MDL\u9501\uff09\n\n# MySQL5.5\u5f15\u5165\u4e86meta data lock\uff0c\u7b80\u79f0MDL\u9501\uff0c\u5c5e\u4e8e\u8868\u9501\u8303\u7574\u3002MDL \u7684\u4f5c\u7528\u662f\uff0c\u4fdd\u8bc1\u8bfb\u5199\u7684\u6b63\u786e\u6027\u3002\u6bd4\u5982\uff0c\n# \u5982\u679c\u4e00\u4e2a\u67e5\u8be2\u6b63\u5728\u904d\u5386\u4e00\u4e2a\u8868\u4e2d\u7684\u6570\u636e\uff0c\u800c\u6267\u884c\u671f\u95f4\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5bf9\u8fd9\u4e2a \u8868\u7ed3\u6784\u505a\u53d8\u66f4 \uff0c\u589e\u52a0\u4e86\u4e00\u5217\uff0c\n# \u90a3\u4e48\u67e5\u8be2\u7ebf\u7a0b\u62ff\u5230\u7684\u7ed3\u679c\u8ddf\u8868\u7ed3\u6784\u5bf9\u4e0d\u4e0a\uff0c\u80af\u5b9a\u662f\u4e0d\u884c\u7684\u3002\n\n# \u56e0\u6b64\uff0c\u5f53\u5bf9\u4e00\u4e2a\u8868\u505a\u589e\u5220\u6539\u67e5\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u52a0 MDL\u8bfb\u9501\uff1b\u5f53\u8981\u5bf9\u8868\u505a\u7ed3\u6784\u53d8\u66f4\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u52a0 MDL \u5199\u9501\u3002\n\nBEGIN;\n\nSELECT * FROM teacher;\n\nCOMMIT;\n\n# 2. InnoDB\u4e2d\u7684\u884c\u9501\n\nSELECT COUNT(*) FROM student;\n\nDROP TABLE student;\n\nCREATE TABLE student(\n    id INT,\n    name VARCHAR(20),\n    class VARCHAR(10),\n    PRIMARY KEY (id)\n)ENGINE=INNODB CHARSET=utf8;\n\nINSERT INTO student\nVALUES (1,'\u5f20\u4e09','\u4e00\u73ed'),\n       (3,'\u674e\u56db','\u4e00\u73ed'),\n       (8,'\u738b\u4e94','\u4e8c\u73ed'),\n       (15,'\u8d75\u516d','\u4e8c\u73ed'),\n       (20,'\u94b1\u4e03','\u4e09\u73ed');\n\nSELECT * FROM student;\n\n# \u2460 \u8bb0\u5f55\u9501\uff08Record Locks\uff09\n\n# \u8bb0\u5f55\u9501\u4e5f\u5c31\u662f\u4ec5\u4ec5\u628a\u4e00\u6761\u8bb0\u5f55\u9501\u4e0a\uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a LOCK_REC_NOT_GAP \u3002\n\nBEGIN;\n\nUPDATE student SET name = '\u5f20\u4e091'\nWHERE id = 1;\n\nCOMMIT;\n\n# \u8bb0\u5f55\u9501\u662f\u6709S\u9501\u548cX\u9501\u4e4b\u5206\u7684\uff0c\u79f0\u4e4b\u4e3a S\u578b\u8bb0\u5f55\u9501 \u548c X\u578b\u8bb0\u5f55\u9501 \u3002\n# \u5f53\u4e00\u4e2a\u4e8b\u52a1\u83b7\u53d6\u4e86\u4e00\u6761\u8bb0\u5f55\u7684S\u578b\u8bb0\u5f55\u9501\u540e\uff0c\u5176\u4ed6\u4e8b\u52a1\u4e5f\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6\u8be5\u8bb0\u5f55\u7684S\u578b\u8bb0\u5f55\u9501\uff0c\n# \u4f46\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6X\u578b\u8bb0\u5f55\u9501\uff1b\n\n# \u5f53\u4e00\u4e2a\u4e8b\u52a1\u83b7\u53d6\u4e86\u4e00\u6761\u8bb0\u5f55\u7684X\u578b\u8bb0\u5f55\u9501\u540e\uff0c\u5176\u4ed6\u4e8b\u52a1\u65e2\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6\u8be5\u8bb0\u5f55\u7684S\u578b\u8bb0\u5f55\u9501\uff0c\n# \u4e5f\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6X\u578b\u8bb0\u5f55\u9501\u3002\n\n# \u2461 \u95f4\u9699\u9501\uff08Gap Locks\uff09\n\n# MySQL \u5728 REPEATABLE READ \u9694\u79bb\u7ea7\u522b\u4e0b\u662f\u53ef\u4ee5\u89e3\u51b3\u5e7b\u8bfb\u95ee\u9898\u7684\uff0c\u89e3\u51b3\u65b9\u6848\u6709\u4e24\u79cd\uff0c\u53ef\u4ee5\u4f7f\u7528 MVCC \u65b9\u6848\u89e3\u51b3\uff0c\n# \u4e5f\u53ef\u4ee5\u91c7\u7528 \u52a0\u9501 \u65b9\u6848\u89e3\u51b3\u3002\u4f46\u662f\u5728\u4f7f\u7528\u52a0\u9501\u65b9\u6848\u89e3\u51b3\u65f6\u6709\u4e2a\u5927\u95ee\u9898\uff0c\u5c31\u662f\u4e8b\u52a1\u5728\u7b2c\u4e00\u6b21\u6267\u884c\u8bfb\u53d6\u64cd\u4f5c\u65f6\uff0c\n# \u90a3\u4e9b\u5e7b\u5f71\u8bb0\u5f55\u5c1a\u4e0d\u5b58\u5728\uff0c\u6211\u4eec\u65e0\u6cd5\u7ed9\u8fd9\u4e9b \u5e7b\u5f71\u8bb0\u5f55 \u52a0\u4e0a \u8bb0\u5f55\u9501 \u3002InnoDB\u63d0\u51fa\u4e86\u4e00\u79cd\u79f0\u4e4b\u4e3aGap Locks \u7684\u9501\uff0c\n# \u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a LOCK_GAP \uff0c\u6211\u4eec\u53ef\u4ee5\u7b80\u79f0\u4e3a gap\u9501 \u3002\n\n# gap\u9501\u7684\u63d0\u51fa\u4ec5\u4ec5\u662f\u4e3a\u4e86\u9632\u6b62\u63d2\u5165\u5e7b\u5f71\u8bb0\u5f55\u800c\u63d0\u51fa\u7684\u3002\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 8 LOCK IN SHARE MODE;\n\nCOMMIT;\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 5 LOCK IN SHARE MODE;\n\nCOMMIT;\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 25 LOCK IN SHARE MODE;\n\nCOMMIT;\n\n#\u95f4\u9699\u9501\u6709\u53ef\u80fd\u5bfc\u81f4\u6b7b\u9501\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 5 LOCK IN SHARE MODE;\n\n#Deadlock found when trying to get lock; try restarting transaction\nINSERT INTO student(id, name, class)\nVALUES (6,'jerry','\u4e00\u73ed');\n\nCOMMIT;\n\n# \u2462 \u4e34\u952e\u9501\uff08Next-Key Locks\uff09\n\n# \u6709\u65f6\u5019\u6211\u4eec\u65e2\u60f3 \u9501\u4f4f\u67d0\u6761\u8bb0\u5f55 \uff0c\u53c8\u60f3 \u963b\u6b62 \u5176\u4ed6\u4e8b\u52a1\u5728\u8be5\u8bb0\u5f55\u524d\u8fb9\u7684 \u95f4\u9699\u63d2\u5165\u65b0\u8bb0\u5f55 \uff0c\n# \u6240\u4ee5InnoDB\u5c31\u63d0\u51fa\u4e86\u4e00\u79cd\u79f0\u4e4b\u4e3a Next-Key Locks \u7684\u9501\uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a LOCK_ORDINARY \uff0c\n# \u6211\u4eec\u4e5f\u53ef\u4ee5\u7b80\u79f0\u4e3a next-key\u9501 \u3002\n# Next-Key Locks\u662f\u5728\u5b58\u50a8\u5f15\u64ce innodb \u3001\u4e8b\u52a1\u7ea7\u522b\u5728 \u53ef\u91cd\u590d\u8bfb \u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u7684\u6570\u636e\u5e93\u9501\uff0c\n# innodb\u9ed8\u8ba4\u7684\u9501\u5c31\u662fNext-Key locks\u3002\n\nSELECT * FROM student;\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id <= 15 AND id > 8 FOR UPDATE;\n\nCOMMIT;\n\n# \u2463 \u63d2\u5165\u610f\u5411\u9501\uff08Insert Intention Locks\uff09\n\n# \u6211\u4eec\u8bf4\u4e00\u4e2a\u4e8b\u52a1\u5728 \u63d2\u5165 \u4e00\u6761\u8bb0\u5f55\u65f6\u9700\u8981\u5224\u65ad\u4e00\u4e0b\u63d2\u5165\u4f4d\u7f6e\u662f\u4e0d\u662f\u88ab\u522b\u7684\u4e8b\u52a1\u52a0\u4e86 gap\u9501\n# \uff08 next-key\u9501\u4e5f\u5305\u542b gap\u9501 \uff09\uff0c\u5982\u679c\u6709\u7684\u8bdd\uff0c\u63d2\u5165\u64cd\u4f5c\u9700\u8981\u7b49\u5f85\uff0c\u76f4\u5230\u62e5\u6709 gap\u9501 \u7684\u90a3\u4e2a\u4e8b\u52a1\u63d0\u4ea4\u3002\n# \u4f46\u662fInnoDB\u89c4\u5b9a\u4e8b\u52a1\u5728\u7b49\u5f85\u7684\u65f6\u5019\u4e5f\u9700\u8981\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e00\u4e2a\u9501\u7ed3\u6784\uff0c\u8868\u660e\u6709\u4e8b\u52a1\u60f3\u5728\u67d0\u4e2a \u95f4\u9699 \u4e2d \u63d2\u5165 \u65b0\u8bb0\u5f55\uff0c\n# \u4f46\u662f\u73b0\u5728\u5728\u7b49\u5f85\u3002InnoDB\u5c31\u628a\u8fd9\u79cd\u7c7b\u578b\u7684\u9501\u547d\u540d\u4e3a Insert Intention Locks \uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a\n# LOCK_INSERT_INTENTION \uff0c\u6211\u4eec\u79f0\u4e3a \u63d2\u5165\u610f\u5411\u9501 \u3002\u63d2\u5165\u610f\u5411\u9501\u662f\u4e00\u79cd Gap\u9501 \uff0c\u4e0d\u662f\u610f\u5411\u9501\uff0c\n# \u5728insert\u64cd\u4f5c\u65f6\u4ea7\u751f\u3002\n\n# \u63d2\u5165\u610f\u5411\u9501\u662f\u5728\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\u884c\u524d\uff0c\u7531 INSERT \u64cd\u4f5c\u4ea7\u751f\u7684\u4e00\u79cd\u95f4\u9699\u9501 \u3002\n\n# \u4e8b\u5b9e\u4e0a\u63d2\u5165\u610f\u5411\u9501\u5e76\u4e0d\u4f1a\u963b\u6b62\u522b\u7684\u4e8b\u52a1\u7ee7\u7eed\u83b7\u53d6\u8be5\u8bb0\u5f55\u4e0a\u4efb\u4f55\u7c7b\u578b\u7684\u9501\u3002\n\nSELECT * FROM student;\n\nBEGIN;\n\nSELECT * FROM student WHERE id = 12 FOR UPDATE;\n\nCOMMIT;\n\n# 3. \u9875\u9501\n\n# \u9875\u9501\u5c31\u662f\u5728 \u9875\u7684\u7c92\u5ea6 \u4e0a\u8fdb\u884c\u9501\u5b9a\uff0c\u9501\u5b9a\u7684\u6570\u636e\u8d44\u6e90\u6bd4\u884c\u9501\u8981\u591a\uff0c\u56e0\u4e3a\u4e00\u4e2a\u9875\u4e2d\u53ef\u4ee5\u6709\u591a\u4e2a\u884c\u8bb0\u5f55\u3002\n# \u5f53\u6211\u4eec\u4f7f\u7528\u9875\u9501\u7684\u65f6\u5019\uff0c\u4f1a\u51fa\u73b0\u6570\u636e\u6d6a\u8d39\u7684\u73b0\u8c61\uff0c\u4f46\u8fd9\u6837\u7684\u6d6a\u8d39\u6700\u591a\u4e5f\u5c31\u662f\u4e00\u4e2a\u9875\u4e0a\u7684\u6570\u636e\u884c\u3002\n# \u9875\u9501\u7684\u5f00\u9500\u4ecb\u4e8e\u8868\u9501\u548c\u884c\u9501\u4e4b\u95f4\uff0c\u4f1a\u51fa\u73b0\u6b7b\u9501\u3002\u9501\u5b9a\u7c92\u5ea6\u4ecb\u4e8e\u8868\u9501\u548c\u884c\u9501\u4e4b\u95f4\uff0c\u5e76\u53d1\u5ea6\u4e00\u822c\u3002\n\n# \u6bcf\u4e2a\u5c42\u7ea7\u7684\u9501\u6570\u91cf\u662f\u6709\u9650\u5236\u7684\uff0c\u56e0\u4e3a\u9501\u4f1a\u5360\u7528\u5185\u5b58\u7a7a\u95f4\uff0c \u9501\u7a7a\u95f4\u7684\u5927\u5c0f\u662f\u6709\u9650\u7684 \u3002\n# \u5f53\u67d0\u4e2a\u5c42\u7ea7\u7684\u9501\u6570\u91cf\u8d85\u8fc7\u4e86\u8fd9\u4e2a\u5c42\u7ea7\u7684\u9608\u503c\u65f6\uff0c\u5c31\u4f1a\u8fdb\u884c \u9501\u5347\u7ea7 \u3002\n# \u9501\u5347\u7ea7\u5c31\u662f\u7528\u66f4\u5927\u7c92\u5ea6\u7684\u9501\u66ff\u4ee3\u591a\u4e2a\u66f4\u5c0f\u7c92\u5ea6\u7684\u9501\uff0c\u6bd4\u5982InnoDB \u4e2d\u884c\u9501\u5347\u7ea7\u4e3a\u8868\u9501\uff0c\n# \u8fd9\u6837\u505a\u7684\u597d\u5904\u662f\u5360\u7528\u7684\u9501\u7a7a\u95f4\u964d\u4f4e\u4e86\uff0c\u4f46\u540c\u65f6\u6570\u636e\u7684\u5e76\u53d1\u5ea6\u4e5f\u4e0b\u964d\u4e86\u3002\n\n# 3.3 \u4ece\u5bf9\u5f85\u9501\u7684\u6001\u5ea6\u5212\u5206:\u4e50\u89c2\u9501\u3001\u60b2\u89c2\u9501\n\n# \u4ece\u5bf9\u5f85\u9501\u7684\u6001\u5ea6\u6765\u770b\u9501\u7684\u8bdd\uff0c\u53ef\u4ee5\u5c06\u9501\u5206\u6210\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\uff0c\n# \u4ece\u540d\u5b57\u4e2d\u4e5f\u53ef\u4ee5\u770b\u51fa\u8fd9\u4e24\u79cd\u9501\u662f\u4e24\u79cd\u770b\u5f85\u6570\u636e\u5e76\u53d1\u7684\u601d\u7ef4\u65b9\u5f0f \u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\n# \u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\u5e76\u4e0d\u662f\u9501\uff0c\u800c\u662f\u9501\u7684 \u8bbe\u8ba1\u601d\u60f3 \u3002\n\n# 1. \u60b2\u89c2\u9501\uff08Pessimistic Locking\uff09\n# \u60b2\u89c2\u9501\u662f\u4e00\u79cd\u601d\u60f3\uff0c\u987e\u540d\u601d\u4e49\uff0c\u5c31\u662f\u5f88\u60b2\u89c2\uff0c\u5bf9\u6570\u636e\u88ab\u5176\u4ed6\u4e8b\u52a1\u7684\u4fee\u6539\u6301\u4fdd\u5b88\u6001\u5ea6\uff0c\n# \u4f1a\u901a\u8fc7\u6570\u636e\u5e93\u81ea\u8eab\u7684\u9501\u673a\u5236\u6765\u5b9e\u73b0\uff0c\u4ece\u800c\u4fdd\u8bc1\u6570\u636e\u64cd\u4f5c\u7684\u6392\u5b83\u6027\u3002\n\n# \u60b2\u89c2\u9501\u603b\u662f\u5047\u8bbe\u6700\u574f\u7684\u60c5\u51b5\uff0c\u6bcf\u6b21\u53bb\u62ff\u6570\u636e\u7684\u65f6\u5019\u90fd\u8ba4\u4e3a\u522b\u4eba\u4f1a\u4fee\u6539\uff0c\u6240\u4ee5\u6bcf\u6b21\u5728\u62ff\u6570\u636e\u7684\u65f6\u5019\u90fd\u4f1a\u4e0a\u9501\uff0c\n# \u8fd9\u6837\u522b\u4eba\u60f3\u62ff\u8fd9\u4e2a\u6570\u636e\u5c31\u4f1a \u963b\u585e \u76f4\u5230\u5b83\u62ff\u5230\u9501\uff08\u5171\u4eab\u8d44\u6e90\u6bcf\u6b21\u53ea\u7ed9\u4e00\u4e2a\u7ebf\u7a0b\u4f7f\u7528\uff0c\u5176\u5b83\u7ebf\u7a0b\u963b\u585e\uff0c\n# \u7528\u5b8c\u540e\u518d\u628a\u8d44\u6e90\u8f6c\u8ba9\u7ed9\u5176\u5b83\u7ebf\u7a0b\uff09\u3002\u6bd4\u5982\u884c\u9501\uff0c\u8868\u9501\u7b49\uff0c\u8bfb\u9501\uff0c\u5199\u9501\u7b49\uff0c\u90fd\u662f\u5728\u505a\u64cd\u4f5c\u4e4b\u524d\u5148\u4e0a\u9501\uff0c\n# \u5f53\u5176\u4ed6\u7ebf\u7a0b\u60f3\u8981\u8bbf\u95ee\u6570\u636e\u65f6\uff0c\u90fd\u9700\u8981\u963b\u585e\u6302\u8d77\u3002\n# Java\u4e2d synchronized \u548c ReentrantLock \u7b49\u72ec\u5360\u9501\u5c31\u662f\u60b2\u89c2\u9501\u601d\u60f3\u7684\u5b9e\u73b0\u3002\n\n# 2. \u4e50\u89c2\u9501\uff08Optimistic Locking\uff09\n# \u4e50\u89c2\u9501\u8ba4\u4e3a\u5bf9\u540c\u4e00\u6570\u636e\u7684\u5e76\u53d1\u64cd\u4f5c\u4e0d\u4f1a\u603b\u53d1\u751f\uff0c\u5c5e\u4e8e\u5c0f\u6982\u7387\u4e8b\u4ef6\uff0c\u4e0d\u7528\u6bcf\u6b21\u90fd\u5bf9\u6570\u636e\u4e0a\u9501\uff0c\n# \u4f46\u662f\u5728\u66f4\u65b0\u7684\u65f6\u5019\u4f1a\u5224\u65ad\u4e00\u4e0b\u5728\u6b64\u671f\u95f4\u522b\u4eba\u6709\u6ca1\u6709\u53bb\u66f4\u65b0\u8fd9\u4e2a\u6570\u636e\uff0c\u4e5f\u5c31\u662f\u4e0d\u91c7\u7528\u6570\u636e\u5e93\u81ea\u8eab\u7684\u9501\u673a\u5236\uff0c\n# \u800c\u662f\u901a\u8fc7\u7a0b\u5e8f\u6765\u5b9e\u73b0\u3002\u5728\u7a0b\u5e8f\u4e0a\uff0c\u6211\u4eec\u53ef\u4ee5\u91c7\u7528 \u7248\u672c\u53f7\u673a\u5236 \u6216\u8005 CAS\u673a\u5236 \u5b9e\u73b0\u3002\n# \u4e50\u89c2\u9501\u9002\u7528\u4e8e\u591a\u8bfb\u7684\u5e94\u7528\u7c7b\u578b\uff0c\u8fd9\u6837\u53ef\u4ee5\u63d0\u9ad8\u541e\u5410\u91cf\u3002\n# \u5728Java\u4e2d java.util.concurrent.atomic \u5305\u4e0b\u7684\u539f\u5b50\u53d8\u91cf\u7c7b\u5c31\u662f\u4f7f\u7528\u4e86\u4e50\u89c2\u9501\u7684\u4e00\u79cd\u5b9e\u73b0\u65b9\u5f0f\uff1aCAS\u5b9e\u73b0\u7684\u3002\n\n# 1. \u4e50\u89c2\u9501\u7684\u7248\u672c\u53f7\u673a\u5236\n# \u5728\u8868\u4e2d\u8bbe\u8ba1\u4e00\u4e2a \u7248\u672c\u5b57\u6bb5 version \uff0c\u7b2c\u4e00\u6b21\u8bfb\u7684\u65f6\u5019\uff0c\u4f1a\u83b7\u53d6 version \u5b57\u6bb5\u7684\u53d6\u503c\u3002\n# \u7136\u540e\u5bf9\u6570\u636e\u8fdb\u884c\u66f4\u65b0\u6216\u5220\u9664\u64cd\u4f5c\u65f6\uff0c\u4f1a\u6267\u884c UPDATE ... SET version=version+1 WHERE version=version \u3002\n# \u6b64\u65f6\u5982\u679c\u5df2\u7ecf\u6709\u4e8b\u52a1\u5bf9\u8fd9\u6761\u6570\u636e\u8fdb\u884c\u4e86\u66f4\u6539\uff0c\u4fee\u6539\u5c31\u4e0d\u4f1a\u6210\u529f\u3002\n\n# 2. \u4e50\u89c2\u9501\u7684\u65f6\u95f4\u6233\u673a\u5236\n# \u65f6\u95f4\u6233\u548c\u7248\u672c\u53f7\u673a\u5236\u4e00\u6837\uff0c\u4e5f\u662f\u5728\u66f4\u65b0\u63d0\u4ea4\u7684\u65f6\u5019\uff0c\u5c06\u5f53\u524d\u6570\u636e\u7684\u65f6\u95f4\u6233\u548c\u66f4\u65b0\u4e4b\u524d\u53d6\u5f97\u7684\u65f6\u95f4\u6233\u8fdb\u884c\u6bd4\u8f83\uff0c\n# \u5982\u679c\u4e24\u8005\u4e00\u81f4\u5219\u66f4\u65b0\u6210\u529f\uff0c\u5426\u5219\u5c31\u662f\u7248\u672c\u51b2\u7a81\u3002\n\n# \u4f60\u80fd\u770b\u5230\u4e50\u89c2\u9501\u5c31\u662f\u7a0b\u5e8f\u5458\u81ea\u5df1\u63a7\u5236\u6570\u636e\u5e76\u53d1\u64cd\u4f5c\u7684\u6743\u9650\uff0c\n# \u57fa\u672c\u662f\u901a\u8fc7\u7ed9\u6570\u636e\u884c\u589e\u52a0\u4e00\u4e2a\u6233\uff08\u7248\u672c\u53f7\u6216\u8005\u65f6\u95f4\u6233\uff09\uff0c\u4ece\u800c\u8bc1\u660e\u5f53\u524d\u62ff\u5230\u7684\u6570\u636e\u662f\u5426\u6700\u65b0\u3002\n\n# 3. \u4e24\u79cd\u9501\u7684\u9002\u7528\u573a\u666f\n# \u4ece\u8fd9\u4e24\u79cd\u9501\u7684\u8bbe\u8ba1\u601d\u60f3\u4e2d\uff0c\u6211\u4eec\u603b\u7ed3\u4e00\u4e0b\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\u7684\u9002\u7528\u573a\u666f\uff1a\n# 1. \u4e50\u89c2\u9501 \u9002\u5408 \u8bfb\u64cd\u4f5c\u591a \u7684\u573a\u666f\uff0c\u76f8\u5bf9\u6765\u8bf4\u5199\u7684\u64cd\u4f5c\u6bd4\u8f83\u5c11\u3002\u5b83\u7684\u4f18\u70b9\u5728\u4e8e \u7a0b\u5e8f\u5b9e\u73b0 \uff0c\n# \u4e0d\u5b58\u5728\u6b7b\u9501\u95ee\u9898\uff0c\u4e0d\u8fc7\u9002\u7528\u573a\u666f\u4e5f\u4f1a\u76f8\u5bf9\u4e50\u89c2\uff0c\u56e0\u4e3a\u5b83\u963b\u6b62\u4e0d\u4e86\u9664\u4e86\u7a0b\u5e8f\u4ee5\u5916\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u3002\n# 2. \u60b2\u89c2\u9501 \u9002\u5408 \u5199\u64cd\u4f5c\u591a \u7684\u573a\u666f\uff0c\u56e0\u4e3a\u5199\u7684\u64cd\u4f5c\u5177\u6709 \u6392\u5b83\u6027 \u3002\u91c7\u7528\u60b2\u89c2\u9501\u7684\u65b9\u5f0f\uff0c\n# \u53ef\u4ee5\u5728\u6570\u636e\u5e93\u5c42\u9762\u963b\u6b62\u5176\u4ed6\u4e8b\u52a1\u5bf9\u8be5\u6570\u636e\u7684\u64cd\u4f5c\u6743\u9650\uff0c\u9632\u6b62 \u8bfb - \u5199 \u548c \u5199 - \u5199 \u7684\u51b2\u7a81\u3002\n\n# 3.4 \u6309\u52a0\u9501\u7684\u65b9\u5f0f\u5212\u5206\uff1a\u663e\u5f0f\u9501\u3001\u9690\u5f0f\u9501\n\n# 1. \u9690\u5f0f\u9501\n# \u60c5\u666f\u4e00\uff1a\u5bf9\u4e8e\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u6765\u8bf4\uff0c\u6709\u4e00\u4e2a trx_id \u9690\u85cf\u5217\uff0c\u8be5\u9690\u85cf\u5217\u8bb0\u5f55\u7740\u6700\u540e\u6539\u52a8\u8be5\u8bb0\u5f55\u7684 \u4e8b\u52a1id \u3002\n# \u90a3\u4e48\u5982\u679c\u5728\u5f53\u524d\u4e8b\u52a1\u4e2d\u65b0\u63d2\u5165\u4e00\u6761\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u540e\uff0c\u8be5\u8bb0\u5f55\u7684 trx_id \u9690\u85cf\u5217\u4ee3\u8868\u7684\u7684\u5c31\u662f\u5f53\u524d\u4e8b\u52a1\u7684 \u4e8b\u52a1id \uff0c\n# \u5982\u679c\u5176\u4ed6\u4e8b\u52a1\u6b64\u65f6\u60f3\u5bf9\u8be5\u8bb0\u5f55\u6dfb\u52a0 S\u9501 \u6216\u8005 X\u9501 \u65f6\uff0c\n# \u9996\u5148\u4f1a\u770b\u4e00\u4e0b\u8be5\u8bb0\u5f55\u7684trx_id \u9690\u85cf\u5217\u4ee3\u8868\u7684\u4e8b\u52a1\u662f\u5426\u662f\u5f53\u524d\u7684\u6d3b\u8dc3\u4e8b\u52a1\uff0c\u5982\u679c\u662f\u7684\u8bdd\uff0c\n# \u90a3\u4e48\u5c31\u5e2e\u52a9\u5f53\u524d\u4e8b\u52a1\u521b\u5efa\u4e00\u4e2a X\u9501 \uff08\u4e5f\u5c31\u662f\u4e3a\u5f53\u524d\u4e8b\u52a1\u521b\u5efa\u4e00\u4e2a\u9501\u7ed3\u6784\uff0c is_waiting \u5c5e\u6027\u662f false \uff09\uff0c\n# \u7136\u540e\u81ea\u5df1\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\uff08\u4e5f\u5c31\u662f\u4e3a\u81ea\u5df1\u4e5f\u521b\u5efa\u4e00\u4e2a\u9501\u7ed3\u6784\uff0c is_waiting \u5c5e\u6027\u662f true \uff09\u3002\n\n# \u60c5\u666f\u4e8c\uff1a\u5bf9\u4e8e\u4e8c\u7ea7\u7d22\u5f15\u8bb0\u5f55\u6765\u8bf4\uff0c\u672c\u8eab\u5e76\u6ca1\u6709 trx_id \u9690\u85cf\u5217\uff0c\n# \u4f46\u662f\u5728\u4e8c\u7ea7\u7d22\u5f15\u9875\u9762\u7684 PageHeader \u90e8\u5206\u6709\u4e00\u4e2a PAGE_MAX_TRX_ID \u5c5e\u6027\uff0c\n# \u8be5\u5c5e\u6027\u4ee3\u8868\u5bf9\u8be5\u9875\u9762\u505a\u6539\u52a8\u7684\u6700\u5927\u7684 \u4e8b\u52a1id \uff0c\u5982\u679c PAGE_MAX_TRX_ID \u5c5e\u6027\u503c\u5c0f\u4e8e\u5f53\u524d\u6700\u5c0f\u7684\u6d3b\u8dc3 \u4e8b\u52a1id \uff0c\n# \u90a3\u4e48\u8bf4\u660e\u5bf9\u8be5\u9875\u9762\u505a\u4fee\u6539\u7684\u4e8b\u52a1\u90fd\u5df2\u7ecf\u63d0\u4ea4\u4e86\uff0c\u5426\u5219\u5c31\u9700\u8981\u5728\u9875\u9762\u4e2d\u5b9a\u4f4d\u5230\u5bf9\u5e94\u7684\u4e8c\u7ea7\u7d22\u5f15\u8bb0\u5f55\uff0c\n# \u7136\u540e\u56de\u8868\u627e\u5230\u5b83\u5bf9\u5e94\u7684\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\uff0c\u7136\u540e\u518d\u91cd\u590d \u60c5\u666f\u4e00 \u7684\u505a\u6cd5\u3002\n\nUSE atguigudb3;\n\nBEGIN;\n\nSELECT * FROM student;\n\nINSERT INTO student(id, name, class)\nVALUES (2,'Tom','\u4e00\u73ed');\n\n# \u9690\u5f0f\u9501\u7684\u903b\u8f91\u8fc7\u7a0b\u5982\u4e0b\uff1a\n# A. InnoDB\u7684\u6bcf\u6761\u8bb0\u5f55\u4e2d\u90fd\u4e00\u4e2a\u9690\u542b\u7684trx_id\u5b57\u6bb5\uff0c\u8fd9\u4e2a\u5b57\u6bb5\u5b58\u5728\u4e8e\u805a\u7c07\u7d22\u5f15\u7684B+Tree\u4e2d\u3002\n# B. \u5728\u64cd\u4f5c\u4e00\u6761\u8bb0\u5f55\u524d\uff0c\u9996\u5148\u6839\u636e\u8bb0\u5f55\u4e2d\u7684trx_id\u68c0\u67e5\u8be5\u4e8b\u52a1\u662f\u5426\u662f\u6d3b\u52a8\u7684\u4e8b\u52a1(\u672a\u63d0\u4ea4\u6216\u56de\u6eda)\u3002\n# \u5982\u679c\u662f\u6d3b\u52a8\u7684\u4e8b\u52a1\uff0c\u9996\u5148\u5c06 \u9690\u5f0f\u9501 \u8f6c\u6362\u4e3a \u663e\u5f0f\u9501 (\u5c31\u662f\u4e3a\u8be5\u4e8b\u52a1\u6dfb\u52a0\u4e00\u4e2a\u9501)\u3002\n# C. \u68c0\u67e5\u662f\u5426\u6709\u9501\u51b2\u7a81\uff0c\u5982\u679c\u6709\u51b2\u7a81\uff0c\u521b\u5efa\u9501\uff0c\u5e76\u8bbe\u7f6e\u4e3awaiting\u72b6\u6001\u3002\u5982\u679c\u6ca1\u6709\u51b2\u7a81\u4e0d\u52a0\u9501\uff0c\u8df3\u5230E\u3002\n# D. \u7b49\u5f85\u52a0\u9501\u6210\u529f\uff0c\u88ab\u5524\u9192\uff0c\u6216\u8005\u8d85\u65f6\u3002\n# E. \u5199\u6570\u636e\uff0c\u5e76\u5c06\u81ea\u5df1\u7684trx_id\u5199\u5165trx_id\u5b57\u6bb5\u3002\n\n# 2. \u663e\u5f0f\u9501\n# \u901a\u8fc7\u7279\u5b9a\u7684\u8bed\u53e5\u8fdb\u884c\u52a0\u9501\uff0c\u6211\u4eec\u4e00\u822c\u79f0\u4e4b\u4e3a\u663e\u793a\u52a0\u9501\uff0c\u4f8b\u5982\uff1a\n\n# \u663e\u793a\u52a0\u5171\u4eab\u9501\uff1a\n# select .... lock in share mode\n\n# \u663e\u793a\u52a0\u6392\u5b83\u9501\uff1a\n# select .... for update\n\n# 3.5 \u5176\u5b83\u9501\u4e4b\uff1a\u5168\u5c40\u9501\n# \u5168\u5c40\u9501\u5c31\u662f\u5bf9 \u6574\u4e2a\u6570\u636e\u5e93\u5b9e\u4f8b \u52a0\u9501\u3002\u5f53\u4f60\u9700\u8981\u8ba9\u6574\u4e2a\u5e93\u5904\u4e8e \u53ea\u8bfb\u72b6\u6001 \u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u547d\u4ee4\uff0c\n# \u4e4b\u540e\u5176\u4ed6\u7ebf\u7a0b\u7684\u4ee5\u4e0b\u8bed\u53e5\u4f1a\u88ab\u963b\u585e\uff1a\u6570\u636e\u66f4\u65b0\u8bed\u53e5\uff08\u6570\u636e\u7684\u589e\u5220\u6539\uff09\u3001\n# \u6570\u636e\u5b9a\u4e49\u8bed\u53e5\uff08\u5305\u62ec\u5efa\u8868\u3001\u4fee\u6539\u8868\u7ed3\u6784\u7b49\uff09\u548c\u66f4\u65b0\u7c7b\u4e8b\u52a1\u7684\u63d0\u4ea4\u8bed\u53e5\u3002\n# \u5168\u5c40\u9501\u7684\u5178\u578b\u4f7f\u7528 \u573a\u666f \u662f\uff1a\u505a \u5168\u5e93\u903b\u8f91\u5907\u4efd \u3002\n\n# \u5168\u5c40\u9501\u7684\u547d\u4ee4\uff1a\n# Flush tables with read lock\n\n# 3.6 \u5176\u5b83\u9501\u4e4b\uff1a\u6b7b\u9501\n# \u6b7b\u9501\u662f\u6307\u4e24\u4e2a\u6216\u591a\u4e2a\u4e8b\u52a1\u5728\u540c\u4e00\u8d44\u6e90\u4e0a\u76f8\u4e92\u5360\u7528\uff0c\u5e76\u8bf7\u6c42\u9501\u5b9a\u5bf9\u65b9\u5360\u7528\u7684\u8d44\u6e90\uff0c\u4ece\u800c\u5bfc\u81f4\u6076\u6027\u5faa\u73af\u3002\n\n# \u5f53\u51fa\u73b0\u6b7b\u9501\u4ee5\u540e\uff0c\u6709 \u4e24\u79cd\u7b56\u7565 \uff1a\n# \u4e00\u79cd\u7b56\u7565\u662f\uff0c\u76f4\u63a5\u8fdb\u5165\u7b49\u5f85\uff0c\u76f4\u5230\u8d85\u65f6\u3002\u8fd9\u4e2a\u8d85\u65f6\u65f6\u95f4\u53ef\u4ee5\u901a\u8fc7\u53c2\u6570 innodb_lock_wait_timeout \u6765\u8bbe\u7f6e\u3002\n\n# \u53e6\u4e00\u79cd\u7b56\u7565\u662f\uff0c\u53d1\u8d77\u6b7b\u9501\u68c0\u6d4b\uff0c\u53d1\u73b0\u6b7b\u9501\u540e\uff0c\n# \u4e3b\u52a8\u56de\u6eda\u6b7b\u9501\u94fe\u6761\u4e2d\u7684\u67d0\u4e00\u4e2a\u4e8b\u52a1\uff08\u5c06\u6301\u6709\u6700\u5c11\u884c\u7ea7\u6392\u4ed6\u9501\u7684\u4e8b\u52a1\u8fdb\u884c\u56de\u6eda\uff09\uff0c\n# \u8ba9\u5176\u4ed6\u4e8b\u52a1\u5f97\u4ee5\u7ee7\u7eed\u6267\u884c\u3002\u5c06\u53c2\u6570 innodb_deadlock_detect \u8bbe\u7f6e\u4e3a on \uff0c\u8868\u793a\u5f00\u542f\u8fd9\u4e2a\u903b\u8f91\u3002\n\n# \u7b2c\u4e8c\u79cd\u7b56\u7565\u7684\u6210\u672c\u5206\u6790\n# \u65b9\u6cd51\uff1a\u5982\u679c\u4f60\u80fd\u786e\u4fdd\u8fd9\u4e2a\u4e1a\u52a1\u4e00\u5b9a\u4e0d\u4f1a\u51fa\u73b0\u6b7b\u9501\uff0c\u53ef\u4ee5\u4e34\u65f6\u628a\u6b7b\u9501\u68c0\u6d4b\u5173\u6389\u3002\n# \u4f46\u662f\u8fd9\u79cd\u64cd\u4f5c\u672c\u8eab\u5e26\u6709\u4e00\u5b9a\u7684\u98ce\u9669\uff0c\u56e0\u4e3a\u4e1a\u52a1\u8bbe\u8ba1\u7684\u65f6\u5019\u4e00\u822c\u4e0d\u4f1a\u628a\u6b7b\u9501\u5f53\u505a\u4e00\u4e2a\u4e25\u91cd\u9519\u8bef\uff0c\u6bd5\u7adf\u51fa\u73b0\u6b7b\u9501\u4e86\uff0c\n# \u5c31\u56de\u6eda\uff0c\u7136\u540e\u901a\u8fc7\u4e1a\u52a1\u91cd\u8bd5\u4e00\u822c\u5c31\u6ca1\u95ee\u9898\u4e86\uff0c\u8fd9\u662f \u4e1a\u52a1\u65e0\u635f \u7684\u3002\u800c\u5173\u6389\u6b7b\u9501\u68c0\u6d4b\u610f\u5473\u7740\u53ef\u80fd\u4f1a\u51fa\u73b0\u5927\u91cf\u7684\u8d85\u65f6\uff0c\n# \u8fd9\u662f\u4e1a\u52a1\u6709\u635f \u7684\u3002\n\n# \u65b9\u6cd52\uff1a\u63a7\u5236\u5e76\u53d1\u5ea6\u3002\n# \u5982\u679c\u5e76\u53d1\u80fd\u591f\u63a7\u5236\u4f4f\uff0c\u6bd4\u5982\u540c\u4e00\u884c\u540c\u65f6\u6700\u591a\u53ea\u670910\u4e2a\u7ebf\u7a0b\u5728\u66f4\u65b0\uff0c\u90a3\u4e48\u6b7b\u9501\u68c0\u6d4b\u7684\u6210\u672c\u5f88\u4f4e\uff0c\u5c31\u4e0d\u4f1a\u51fa\u73b0\u8fd9\u4e2a\u95ee\u9898\u3002\n\n# \u8fd9\u4e2a\u5e76\u53d1\u63a7\u5236\u8981\u505a\u5728 \u6570\u636e\u5e93\u670d\u52a1\u7aef \u3002\u5982\u679c\u4f60\u6709\u4e2d\u95f4\u4ef6\uff0c\u53ef\u4ee5\u8003\u8651\u5728 \u4e2d\u95f4\u4ef6\u5b9e\u73b0 \uff1b\n# \u751a\u81f3\u6709\u80fd\u529b\u4fee\u6539MySQL\u6e90\u7801\u7684\u4eba\uff0c\u4e5f\u53ef\u4ee5\u505a\u5728MySQL\u91cc\u9762\u3002\u57fa\u672c\u601d\u8def\u5c31\u662f\uff0c\u5bf9\u4e8e\u76f8\u540c\u884c\u7684\u66f4\u65b0\uff0c\u5728\u8fdb\u5165\u5f15\u64ce\u4e4b\u524d\u6392\u961f\uff0c\n# \u8fd9\u6837\u5728InnoDB\u5185\u90e8\u5c31\u4e0d\u4f1a\u6709\u5927\u91cf\u7684\u6b7b\u9501\u68c0\u6d4b\u5de5\u4f5c\u4e86\u3002\n\nUSE atguigudb3;\n\nSELECT * FROM account;\n\n# \u2462 \u5982\u4f55\u5904\u7406\u6b7b\u9501\n\n# \u65b9\u5f0f1\uff1a\u7b49\u5f85\uff0c\u76f4\u5230\u8d85\u65f6\uff08innodb_lock_wait_timeout=50s\uff09\u3002\n#\u67e5\u770b\u8d85\u65f6\u65f6\u95f4\nSHOW VARIABLES LIKE 'innodb_lock_wait_timeout';\n\n# \u65b9\u5f0f2\uff1a\u4f7f\u7528\u6b7b\u9501\u68c0\u6d4b\u8fdb\u884c\u601d\u7d22\u5904\u7406\nBEGIN;\n\nUPDATE account SET balance = balance - 10 WHERE id = 1;\n\nUPDATE account SET balance = balance + 10 WHERE id = 3;\n\nCOMMIT;\n\n# 4. \u9501\u7684\u5185\u5b58\u7ed3\u6784\n\n# InnoDB \u5b58\u50a8\u5f15\u64ce\u4e2d\u7684 \u9501\u7ed3\u6784\n\n# 1. \u9501\u6240\u5728\u7684\u4e8b\u52a1\u4fe1\u606f \uff1a\n# \u4e0d\u8bba\u662f \u8868\u9501 \u8fd8\u662f \u884c\u9501 \uff0c\u90fd\u662f\u5728\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u751f\u6210\u7684\uff0c\u54ea\u4e2a\u4e8b\u52a1\u751f\u6210\u4e86\u8fd9\u4e2a \u9501\u7ed3\u6784 \uff0c\n# \u8fd9\u91cc\u5c31\u8bb0\u5f55\u8fd9\u4e2a\u4e8b\u52a1\u7684\u4fe1\u606f\u3002\n\n# \u6b64 \u9501\u6240\u5728\u7684\u4e8b\u52a1\u4fe1\u606f \u5728\u5185\u5b58\u7ed3\u6784\u4e2d\u53ea\u662f\u4e00\u4e2a\u6307\u9488\uff0c\u901a\u8fc7\u6307\u9488\u53ef\u4ee5\u627e\u5230\u5185\u5b58\u4e2d\u5173\u4e8e\u8be5\u4e8b\u52a1\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u6bd4\u65b9\u8bf4\u4e8b\u52a1id\u7b49\u3002\n\n# 2. \u7d22\u5f15\u4fe1\u606f \uff1a\n# \u5bf9\u4e8e \u884c\u9501 \u6765\u8bf4\uff0c\u9700\u8981\u8bb0\u5f55\u4e00\u4e0b\u52a0\u9501\u7684\u8bb0\u5f55\u662f\u5c5e\u4e8e\u54ea\u4e2a\u7d22\u5f15\u7684\u3002\u8fd9\u91cc\u4e5f\u662f\u4e00\u4e2a\u6307\u9488\u3002\n\n# 3. \u8868\u9501\uff0f\u884c\u9501\u4fe1\u606f \uff1a\n# \u8868\u9501\u7ed3\u6784 \u548c \u884c\u9501\u7ed3\u6784 \u5728\u8fd9\u4e2a\u4f4d\u7f6e\u7684\u5185\u5bb9\u662f\u4e0d\u540c\u7684\uff1a\n\n# \u8868\u9501\uff1a\n# \u8bb0\u8f7d\u7740\u662f\u5bf9\u54ea\u4e2a\u8868\u52a0\u7684\u9501\uff0c\u8fd8\u6709\u5176\u4ed6\u7684\u4e00\u4e9b\u4fe1\u606f\u3002\n\n# \u884c\u9501\uff1a\n# \u8bb0\u8f7d\u4e86\u4e09\u4e2a\u91cd\u8981\u7684\u4fe1\u606f\uff1a\n# Space ID \uff1a\u8bb0\u5f55\u6240\u5728\u8868\u7a7a\u95f4\u3002\n# Page Number \uff1a\u8bb0\u5f55\u6240\u5728\u9875\u53f7\u3002\n# n_bits \uff1a\u5bf9\u4e8e\u884c\u9501\u6765\u8bf4\uff0c\u4e00\u6761\u8bb0\u5f55\u5c31\u5bf9\u5e94\u7740\u4e00\u4e2a\u6bd4\u7279\u4f4d\uff0c\u4e00\u4e2a\u9875\u9762\u4e2d\u5305\u542b\u5f88\u591a\u8bb0\u5f55\uff0c\n# \u7528\u4e0d\u540c\u7684\u6bd4\u7279\u4f4d\u6765\u533a\u5206\u5230\u5e95\u662f\u54ea\u4e00\u6761\u8bb0\u5f55\u52a0\u4e86\u9501\u3002\u4e3a\u6b64\u5728\u884c\u9501\u7ed3\u6784\u7684\u672b\u5c3e\u653e\u7f6e\u4e86\u4e00\u5806\u6bd4\u7279\u4f4d\uff0c\n# \u8fd9\u4e2an_bits \u5c5e\u6027\u4ee3\u8868\u4f7f\u7528\u4e86\u591a\u5c11\u6bd4\u7279\u4f4d\u3002\n\n# n_bits\u7684\u503c\u4e00\u822c\u90fd\u6bd4\u9875\u9762\u4e2d\u8bb0\u5f55\u6761\u6570\u591a\u4e00\u4e9b\u3002\u4e3b\u8981\u662f\u4e3a\u4e86\u4e4b\u540e\u5728\u9875\u9762\u4e2d\u63d2\u5165\u4e86\u65b0\u8bb0\u5f55\u540e\u4e5f\u4e0d\u81f3\u4e8e\u91cd\u65b0\u5206\u914d\u9501\u7ed3\u6784\n\n# 4. type_mode \uff1a\n# \u8fd9\u662f\u4e00\u4e2a32\u4f4d\u7684\u6570\uff0c\u88ab\u5206\u6210\u4e86 lock_mode \u3001 lock_type \u548c rec_lock_type \u4e09\u4e2a\u90e8\u5206\uff0c\n\n# \u9501\u7684\u6a21\u5f0f\uff08 lock_mode \uff09\uff0c\u5360\u7528\u4f4e4\u4f4d\uff0c\u53ef\u9009\u7684\u503c\u5982\u4e0b\uff1a\n# LOCK_IS \uff08\u5341\u8fdb\u5236\u7684 0 \uff09\uff1a\u8868\u793a\u5171\u4eab\u610f\u5411\u9501\uff0c\u4e5f\u5c31\u662f IS\u9501 \u3002\n# LOCK_IX \uff08\u5341\u8fdb\u5236\u7684 1 \uff09\uff1a\u8868\u793a\u72ec\u5360\u610f\u5411\u9501\uff0c\u4e5f\u5c31\u662f IX\u9501 \u3002\n# LOCK_S \uff08\u5341\u8fdb\u5236\u7684 2 \uff09\uff1a\u8868\u793a\u5171\u4eab\u9501\uff0c\u4e5f\u5c31\u662f S\u9501 \u3002\n# LOCK_X \uff08\u5341\u8fdb\u5236\u7684 3 \uff09\uff1a\u8868\u793a\u72ec\u5360\u9501\uff0c\u4e5f\u5c31\u662f X\u9501 \u3002\n# LOCK_AUTO_INC \uff08\u5341\u8fdb\u5236\u7684 4 \uff09\uff1a\u8868\u793a AUTO-INC\u9501 \u3002\n\n# \u5728InnoDB\u5b58\u50a8\u5f15\u64ce\u4e2d\uff0cLOCK_IS\uff0cLOCK_IX\uff0cLOCK_AUTO_INC\u90fd\u7b97\u662f\u8868\u7ea7\u9501\u7684\u6a21\u5f0f\uff0c\n# LOCK_S\u548cLOCK_X\u65e2\u53ef\u4ee5\u7b97\u662f\u8868\u7ea7\u9501\u7684\u6a21\u5f0f\uff0c\u4e5f\u53ef\u4ee5\u662f\u884c\u7ea7\u9501\u7684\u6a21\u5f0f\u3002\n\n# \u9501\u7684\u7c7b\u578b\uff08 lock_type \uff09\uff0c\u5360\u7528\u7b2c5\uff5e8\u4f4d\uff0c\u4e0d\u8fc7\u73b0\u9636\u6bb5\u53ea\u6709\u7b2c5\u4f4d\u548c\u7b2c6\u4f4d\u88ab\u4f7f\u7528\uff1a\n# LOCK_TABLE \uff08\u5341\u8fdb\u5236\u7684 16 \uff09\uff0c\u4e5f\u5c31\u662f\u5f53\u7b2c5\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u8868\u7ea7\u9501\u3002\n# LOCK_REC \uff08\u5341\u8fdb\u5236\u7684 32 \uff09\uff0c\u4e5f\u5c31\u662f\u5f53\u7b2c6\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u884c\u7ea7\u9501\u3002\n\n# \u884c\u9501\u7684\u5177\u4f53\u7c7b\u578b\uff08 rec_lock_type \uff09\uff0c\u4f7f\u7528\u5176\u4f59\u7684\u4f4d\u6765\u8868\u793a\u3002\u53ea\u6709\u5728 lock_type \u7684\u503c\u4e3aLOCK_REC \u65f6\uff0c\n# \u4e5f\u5c31\u662f\u53ea\u6709\u5728\u8be5\u9501\u4e3a\u884c\u7ea7\u9501\u65f6\uff0c\u624d\u4f1a\u88ab\u7ec6\u5206\u4e3a\u66f4\u591a\u7684\u7c7b\u578b\uff1a\n# LOCK_ORDINARY \uff08\u5341\u8fdb\u5236\u7684 0 \uff09\uff1a\u8868\u793a next-key\u9501 \u3002\n# LOCK_GAP \uff08\u5341\u8fdb\u5236\u7684 512 \uff09\uff1a\u4e5f\u5c31\u662f\u5f53\u7b2c10\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a gap\u9501 \u3002\n# LOCK_REC_NOT_GAP \uff08\u5341\u8fdb\u5236\u7684 1024 \uff09\uff1a\u4e5f\u5c31\u662f\u5f53\u7b2c11\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u6b63\u7ecf \u8bb0\u5f55\u9501 \u3002\n# LOCK_INSERT_INTENTION \uff08\u5341\u8fdb\u5236\u7684 2048 \uff09\uff1a\u4e5f\u5c31\u662f\u5f53\u7b2c12\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u63d2\u5165\u610f\u5411\u9501\u3002\n# \u5176\u4ed6\u7684\u7c7b\u578b\uff1a\u8fd8\u6709\u4e00\u4e9b\u4e0d\u5e38\u7528\u7684\u7c7b\u578b\u6211\u4eec\u5c31\u4e0d\u591a\u8bf4\u4e86\u3002\n\n# is_waiting \u5c5e\u6027\u5462\uff1f\u57fa\u4e8e\u5185\u5b58\u7a7a\u95f4\u7684\u8282\u7701\uff0c\u6240\u4ee5\u628a is_waiting \u5c5e\u6027\u653e\u5230\u4e86 type_mode \u8fd9\u4e2a32\u4f4d\u7684\u6570\u5b57\u4e2d\uff1a\n# LOCK_WAIT \uff08\u5341\u8fdb\u5236\u7684 256 \uff09 \uff1a\u5f53\u7b2c9\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a 1 \u65f6\uff0c\u8868\u793a is_waiting \u4e3a true \uff0c\n# \u4e5f\u5c31\u662f\u5f53\u524d\u4e8b\u52a1\u5c1a\u672a\u83b7\u53d6\u5230\u9501\uff0c\u5904\u5728\u7b49\u5f85\u72b6\u6001\uff1b\u5f53\u8fd9\u4e2a\u6bd4\u7279\u4f4d\u4e3a 0 \u65f6\uff0c\u8868\u793a is_waiting \u4e3afalse \uff0c\n# \u4e5f\u5c31\u662f\u5f53\u524d\u4e8b\u52a1\u83b7\u53d6\u9501\u6210\u529f\u3002\n\n# 5. \u5176\u4ed6\u4fe1\u606f \uff1a\n# \u4e3a\u4e86\u66f4\u597d\u7684\u7ba1\u7406\u7cfb\u7edf\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u751f\u6210\u7684\u5404\u79cd\u9501\u7ed3\u6784\u800c\u8bbe\u8ba1\u4e86\u5404\u79cd\u54c8\u5e0c\u8868\u548c\u94fe\u8868\u3002\n\n# 6. \u4e00\u5806\u6bd4\u7279\u4f4d \uff1a\n# \u5982\u679c\u662f \u884c\u9501\u7ed3\u6784 \u7684\u8bdd\uff0c\u5728\u8be5\u7ed3\u6784\u672b\u5c3e\u8fd8\u653e\u7f6e\u4e86\u4e00\u5806\u6bd4\u7279\u4f4d\uff0c\u6bd4\u7279\u4f4d\u7684\u6570\u91cf\u662f\u7531\u4e0a\u8fb9\u63d0\u5230\u7684 n_bits \u5c5e\u6027\u8868\u793a\u7684\u3002\n# InnoDB\u6570\u636e\u9875\u4e2d\u7684\u6bcf\u6761\u8bb0\u5f55\u5728 \u8bb0\u5f55\u5934\u4fe1\u606f \u4e2d\u90fd\u5305\u542b\u4e00\u4e2a heap_no \u5c5e\u6027\uff0c\u4f2a\u8bb0\u5f55 Infimum \u7684heap_no \u503c\u4e3a 0 \uff0c\n# Supremum \u7684 heap_no \u503c\u4e3a 1 \uff0c\u4e4b\u540e\u6bcf\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\uff0c heap_no \u503c\u5c31\u589e1\u3002\n# \u9501\u7ed3\u6784 \u6700\u540e\u7684\u4e00\u5806\u6bd4\u7279\u4f4d\u5c31\u5bf9\u5e94\u7740\u4e00\u4e2a\u9875\u9762\u4e2d\u7684\u8bb0\u5f55\uff0c\u4e00\u4e2a\u6bd4\u7279\u4f4d\u6620\u5c04\u4e00\u4e2a heap_no \uff0c\u5373\u4e00\u4e2a\u6bd4\u7279\u4f4d\u6620\u5c04\u5230\u9875\u5185\u7684\u4e00\u6761\u8bb0\u5f55\u3002\n\n# 5. \u9501\u76d1\u63a7\n\n# \u5173\u4e8eMySQL\u9501\u7684\u76d1\u63a7\uff0c\u6211\u4eec\u4e00\u822c\u53ef\u4ee5\u901a\u8fc7\u68c0\u67e5 InnoDB_row_lock \u7b49\u72b6\u6001\u53d8\u91cf\u6765\u5206\u6790\u7cfb\u7edf\u4e0a\u7684\u884c\u9501\u7684\u4e89\u593a\u60c5\u51b5\nSHOW STATUS LIKE 'innodb_row_lock%';\n\n# \u5bf9\u5404\u4e2a\u72b6\u6001\u91cf\u7684\u8bf4\u660e\u5982\u4e0b\uff1a\n# Innodb_row_lock_current_waits\uff1a\u5f53\u524d\u6b63\u5728\u7b49\u5f85\u9501\u5b9a\u7684\u6570\u91cf\uff1b\n# Innodb_row_lock_time \uff1a\u4ece\u7cfb\u7edf\u542f\u52a8\u5230\u73b0\u5728\u9501\u5b9a\u603b\u65f6\u95f4\u957f\u5ea6\uff1b\uff08\u7b49\u5f85\u603b\u65f6\u957f\uff09\n# Innodb_row_lock_time_avg \uff1a\u6bcf\u6b21\u7b49\u5f85\u6240\u82b1\u5e73\u5747\u65f6\u95f4\uff1b\uff08\u7b49\u5f85\u5e73\u5747\u65f6\u957f\uff09\n# Innodb_row_lock_time_max\uff1a\u4ece\u7cfb\u7edf\u542f\u52a8\u5230\u73b0\u5728\u7b49\u5f85\u6700\u5e38\u7684\u4e00\u6b21\u6240\u82b1\u7684\u65f6\u95f4\uff1b\n# Innodb_row_lock_waits \uff1a\u7cfb\u7edf\u542f\u52a8\u540e\u5230\u73b0\u5728\u603b\u5171\u7b49\u5f85\u7684\u6b21\u6570\uff1b\uff08\u7b49\u5f85\u603b\u6b21\u6570\uff09\n\n# \u5bf9\u4e8e\u8fd95\u4e2a\u72b6\u6001\u53d8\u91cf\uff0c\u6bd4\u8f83\u91cd\u8981\u76843\u4e2a\u89c1\u4e0a\u9762(2,3,5)\u3002\n\n# \u5176\u4ed6\u76d1\u63a7\u65b9\u6cd5\uff1a\n# MySQL\u628a\u4e8b\u52a1\u548c\u9501\u7684\u4fe1\u606f\u8bb0\u5f55\u5728\u4e86 information_schema \u5e93\u4e2d\uff0c\n# \u6d89\u53ca\u5230\u7684\u4e09\u5f20\u8868\u5206\u522b\u662fINNODB_TRX\u3001INNODB_LOCKS \u548c INNODB_LOCK_WAITS \u3002\n\n# MySQL5.7\u53ca\u4e4b\u524d \uff0c\u53ef\u4ee5\u901a\u8fc7information_schema.INNODB_LOCKS\u67e5\u770b\u4e8b\u52a1\u7684\u9501\u60c5\u51b5\uff0c\u4f46\u53ea\u80fd\u770b\u5230\u963b\u585e\u4e8b\u52a1\u7684\u9501\uff1b\n# \u5982\u679c\u4e8b\u52a1\u5e76\u672a\u88ab\u963b\u585e\uff0c\u5219\u5728\u8be5\u8868\u4e2d\u770b\u4e0d\u5230\u8be5\u4e8b\u52a1\u7684\u9501\u60c5\u51b5\u3002\n\n# MySQL8.0\u5220\u9664\u4e86information_schema.INNODB_LOCKS\uff0c\u6dfb\u52a0\u4e86 performance_schema.data_locks \uff0c\n# \u53ef\u4ee5\u901a\u8fc7performance_schema.data_locks\u67e5\u770b\u4e8b\u52a1\u7684\u9501\u60c5\u51b5\uff0c\u548cMySQL5.7\u53ca\u4e4b\u524d\u4e0d\u540c\uff0c\n# performance_schema.data_locks\u4e0d\u4f46\u53ef\u4ee5\u770b\u5230\u963b\u585e\u8be5\u4e8b\u52a1\u7684\u9501\uff0c\u8fd8\u53ef\u4ee5\u770b\u5230\u8be5\u4e8b\u52a1\u6240\u6301\u6709\u7684\u9501\u3002\n\n# \u540c\u65f6\uff0cinformation_schema.INNODB_LOCK_WAITS\u4e5f\u88ab performance_schema.data_lock_waits \u6240\u4ee3\u66ff\u3002\n\nBEGIN;\n\nSELECT * FROM student FOR UPDATE;\n\nCOMMIT;\n\nSELECT * FROM information_schema.INNODB_TRX;\n\nSELECT * FROM performance_schema.data_locks;\n\nSELECT * FROM performance_schema.data_lock_waits;\n\n\n\n<\/code><\/pre>\n\n\n\n
# \u7b2c15\u7ae0_\u9501\n\n# 3. \u9501\u7684\u4e0d\u540c\u89d2\u5ea6\u5206\u7c7b\n\n# 3.1 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c7b\u578b\u5212\u5206\uff1a\u8bfb\u9501\u3001\u5199\u9501\n\nuse atguigudb3;\n\nbegin;\n\n#\u5171\u4eab\u9501 s\u9501\nselect * from account lock in share mode;\n\ncommit;\n\nselect * from account lock in share mode;   #\u963b\u585e\n\ncommit;\n\n# 3.2 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\uff1a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u3001\u884c\u9501\n\n# 1. \u8868\u9501\uff08Table Lock\uff09\n\n# \u2460 \u8868\u7ea7\u522b\u7684S\u9501\u3001X\u9501\n\nSELECT * FROM mylock;\n\nUPDATE mylock SET name = 'a2' WHERE id = 1;\n\nSELECT * FROM mylock;\n\nSELECT * FROM mylock;\n\nUPDATE mylock SET name = 'a5' WHERE id = 1;\n\n# \u2461 \u610f\u5411\u9501 \uff08intention lock\uff09\n\nSELECT * FROM teacher;\n\nBEGIN;\n\nLOCK TABLES teacher READ;\n\nUNLOCK TABLES;\n\nBEGIN;\n\nSELECT * FROM teacher\nWHERE id = 6 FOR UPDATE;\n\nSELECT * FROM teacher\nWHERE id = 5 FOR UPDATE;\n\n# \u2463 \u5143\u6570\u636e\u9501\uff08MDL\u9501\uff09\n\nBEGIN;\n\nALTER TABLE teacher ADD age INT;\n\nALTER TABLE teacher ADD age INT;\n\nCOMMIT;\n\n# 2. InnoDB\u4e2d\u7684\u884c\u9501\n\nSELECT * FROM student;\n\n# \u2460 \u8bb0\u5f55\u9501\uff08Record Locks\uff09\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 2 LOCK IN SHARE MODE;\n\nSELECT * FROM student\nWHERE id = 3 LOCK IN SHARE MODE;\n\nSELECT * FROM student\nWHERE id = 1 LOCK IN SHARE MODE;\n\nUPDATE student SET name = '\u674e\u56db1'\nWHERE id = 3;\n\nUPDATE student SET name = '\u5f20\u4e093'\nWHERE id = 1;\n\nSELECT * FROM student;\n\n# \u2461 \u95f4\u9699\u9501\uff08Gap Locks\uff09\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 8 FOR UPDATE;\n\nCOMMIT;\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 5 FOR UPDATE;\n\nCOMMIT;\n\n#\u95f4\u9699\u9501\u6709\u53ef\u80fd\u5bfc\u81f4\u6b7b\u9501\n\nBEGIN;\n\nSELECT * FROM student\nWHERE id = 5 LOCK IN SHARE MODE;\n\nINSERT INTO student(id, name, class)\nVALUES (7,'jerry','\u4e00\u73ed');\n\nCOMMIT;\n\n# \u2462 \u4e34\u952e\u9501\uff08Next-Key Locks\uff09\n\nBEGIN;\n\nSELECT * FROM student WHERE id = 15 LOCK IN SHARE MODE;\n\nSELECT * FROM student WHERE id = 15 FOR UPDATE;\n\nINSERT INTO student(id, name, class)\nVALUES(12,'Tim','\u4e00\u73ed');\n\nCOMMIT;\n\n# \u2463 \u63d2\u5165\u610f\u5411\u9501\uff08Insert Intention Locks\uff09\n\nBEGIN;\n\nINSERT INTO student(id, name, class)\nVALUES(11,'Tim','\u4e00\u73ed');\n\nINSERT INTO student(id, name, class)\nVALUES(11,'Tim','\u4e00\u73ed');\n\n# 3.4 \u6309\u52a0\u9501\u7684\u65b9\u5f0f\u5212\u5206\uff1a\u663e\u5f0f\u9501\u3001\u9690\u5f0f\u9501\n\n# 1. \u9690\u5f0f\u9501\n\nUSE atguigudb3;\n\nBEGIN;\n\nSELECT * FROM student LOCK IN SHARE MODE;\n\n# 3.6 \u5176\u5b83\u9501\u4e4b\uff1a\u6b7b\u9501\n\nUSE atguigudb3;\n\nBEGIN;\n\nSELECT * FROM account;\n\nUPDATE account SET balance = balance - 10 WHERE id = 3;\n\nUPDATE account SET balance = balance + 10 WHERE id = 1;\n\nCOMMIT;\n\n# 5. \u9501\u76d1\u63a7\n\nBEGIN;\n\nSELECT * FROM student FOR UPDATE;\n\nCOMMIT;\n<\/code><\/pre>\n\n\n\n
# \u7b2c15\u7ae0_\u9501\n\n# 3. \u9501\u7684\u4e0d\u540c\u89d2\u5ea6\u5206\u7c7b\n\n# 3.1 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c7b\u578b\u5212\u5206\uff1a\u8bfb\u9501\u3001\u5199\u9501\u3001\n\nuse atguigudb3;\n\nbegin;\n\n#\u6392\u4ed6\u9501 x\u9501\nselect * from account for update;   #\u963b\u585e\n\ncommit;\n\nbegin;\n\n#NOWAIT\u4f1a\u7acb\u5373\u62a5\u9519\u8fd4\u56de\nselect * from account for update nowait;\n\n#SKIP LOCKED\u4e5f\u4f1a\u7acb\u5373\u8fd4\u56de\uff0c\u53ea\u662f\u8fd4\u56de\u7684\u7ed3\u679c\u4e2d\u4e0d\u5305\u542b\u88ab\u9501\u5b9a\u7684\u884c\u3002\nselect * from account for update skip locked;\n\ncommit;\n\n# 3.2 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\uff1a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u3001\u884c\u9501\n\n# 1. \u8868\u9501\uff08Table Lock\uff09\n\n# \u2463 \u5143\u6570\u636e\u9501\uff08MDL\u9501\uff09\n\nSHOW PROCESSLIST;\n\nBEGIN;\n\nSELECT * FROM teacher;\n\nCOMMIT;\n\nBEGIN;\n\nSELECT * FROM teacher;\n\nCOMMIT;\n\n# 2. InnoDB\u4e2d\u7684\u884c\u9501\n\n# \u2461 \u95f4\u9699\u9501\uff08Gap Locks\uff09\n\nBEGIN;\n\nINSERT INTO student(id, name, class)\nVALUES(6,'tom','\u4e09\u73ed');\n\nCOMMIT;\n\nINSERT INTO student(id, name, class)\nVALUES(21,'tom','\u4e09\u73ed');\n\nINSERT INTO student(id, name, class)\nVALUES(22,'tom','\u4e09\u73ed');\n\nINSERT INTO student(id, name, class)\nVALUES(26,'tom','\u4e09\u73ed');\n\nINSERT INTO student(id, name, class)\nVALUES(17,'tom','\u4e09\u73ed');\n\nSELECT * FROM performance_schema.data_locks;\n\nCOMMIT;\n\n# \u2463 \u63d2\u5165\u610f\u5411\u9501\uff08Insert Intention Locks\uff09\n\nBEGIN;\n\nINSERT INTO student(id, name, class)\nVALUES(12,'Tim','\u4e00\u73ed');\n\nCOMMIT;\n# 3.4 \u6309\u52a0\u9501\u7684\u65b9\u5f0f\u5212\u5206\uff1a\u663e\u5f0f\u9501\u3001\u9690\u5f0f\u9501\n\n# 1. \u9690\u5f0f\u9501\n\nSELECT * FROM performance_schema.data_lock_waits;\n\n# 5. \u9501\u76d1\u63a7\n\nSELECT * FROM information_schema.INNODB_TRX;\n\nSELECT * FROM performance_schema.data_locks;\n\nSELECT * FROM performance_schema.data_lock_waits;\n\n<\/code><\/pre>\n\n\n\n
3.2 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\uff1a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u3001\u884c\u9501 <\/h3>\n\n\n\n
1. \u8868\u9501\uff08Table Lock\uff09<\/h4>\n\n\n\n
\u2461 \u610f\u5411\u9501 \uff08intention lock\uff09<\/p>\n\n\n\n
\u610f\u5411\u9501\u4e4b\u95f4\u7684\u517c\u5bb9\u4e92\u65a5\u6027<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n","protected":false},"excerpt":{"rendered":"
3.2 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\uff1a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u3001\u884c\u9501 1. \u8868\u9501\uff08Table Lock\uff09 \u2461 \u610f\u5411\u9501 \uff08inte […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[47],"class_list":["post-1684","post","type-post","status-publish","format-standard","hentry","category-mysql-code","tag-mysql"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1684"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1684"}],"version-history":[{"count":2,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1684\/revisions"}],"predecessor-version":[{"id":1696,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1684\/revisions\/1696"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1684"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}