MySQL MySQL的慢查询日志中的时间单位是什么？
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What is the unit of time in MySQL's slow-query log?
提问by aroth
I'm looking at the slow query log from a drupal-based webapp, and have lines that look like this:
我正在查看来自基于 drupal 的 web 应用程序的慢查询日志，并且有如下所示的行：
# Query_time: 3257 Lock_time: 0 Rows_sent: 272 Rows_examined: 272
# Query_time: 1654 Lock_time: 0 Rows_sent: 222 Rows_examined: 222
# Query_time: 3292 Lock_time: 0 Rows_sent: 269 Rows_examined: 269
# Query_time: 1029 Lock_time: 0 Rows_sent: 172 Rows_examined: 172
# Query_time: 2126 Lock_time: 0 Rows_sent: 251 Rows_examined: 251
# Query_time: 1731 Lock_time: 0 Rows_sent: 229 Rows_examined: 229
Are these times indicating that the associated queries took between 1 and 3+ seconds (slow but not terrible) to execute, or between 1,000 and 3,000+ seconds (completely unacceptable)? I understand that the long_query_timeoption is specified in seconds, but do the log messages follow this same convention, or do they use milliseconds instead?
这些时间是否表明相关查询的执行时间在 1 到 3+ 秒之间（缓慢但并不可怕），或者在 1,000 到 3,000+ 秒之间（完全不可接受）？我知道该long_query_time选项以秒为单位指定，但日志消息是否遵循相同的约定，还是使用毫秒？
Edit: this is with MySQL version 5.0.45.
编辑：这是 MySQL 5.0.45 版。
采纳答案by Mchl
It's in seconds. The 'resolution of microseconds' means, that you can have up to microsecond precision after a decimal (although AFAIK it need a patch to actually write with such precision)
它在几秒钟内。“微秒分辨率”意味着，您可以在小数点后获得高达微秒的精度（尽管 AFAIK 它需要一个补丁才能以这种精度实际写入）
https://github.com/wvanbergen/request-log-analyzer/wiki/MySQL-slow-query-log
https://github.com/wvanbergen/request-log-analyzer/wiki/MySQL-slow-query-log
回答by jcisio
Only since MySQL 5.1.21 that you can specify a decimal value and has a resolution of microsecond. http://dev.mysql.com/doc/refman/5.1/en/slow-query-log.html
仅从 MySQL 5.1.21 开始，您可以指定十进制值并具有微秒分辨率。 http://dev.mysql.com/doc/refman/5.1/en/slow-query-log.html
