MySQL执行update语句和原数据相同会再次执行吗-创新互联
背景
本文主要测试MySQL执行update语句时,针对与原数据(即未修改)相同的update语句会在MySQL内部重新执行吗?
测试环境
- MySQL5.7.25
- Centos 7.4
binlog_format为ROW
参数
root@localhost : (none) 04:53:15> show variables like 'binlog_row_image'; +------------------+-------+ | Variable_name | Value | +------------------+-------+ | binlog_row_image | FULL | +------------------+-------+ 1 row in set (0.00 sec) root@localhost : (none) 04:53:49> show variables like 'binlog_format'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | binlog_format | ROW | +---------------+-------+ 1 row in set (0.00 sec) root@localhost : test 05:15:14> show variables like 'transaction_isolation'; +-----------------------+-----------------+ | Variable_name | Value | +-----------------------+-----------------+ | transaction_isolation | REPEATABLE-READ | +-----------------------+-----------------+ 1 row in set (0.00 sec)
分享名称:MySQL执行update语句和原数据相同会再次执行吗-创新互联
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