Re: MySQL query execution time differs between executions

[Ofer Bechar]

Thanks for your answer Peter,

The server dedicated to MySQL is a 8GB RAM server.
The innodb_buffer_pool_size is 6GB.

I think it is not the query cache, because of 3 reasons:

1. The query is never the same because it is limited by time range. Everytime you run the query, the time range changes so the query is never the same query.
2. When it is fast, running the query with "sql_no_cache" option results the same execution time as running it without "sql_no_cache".
3. When it is fast, and I select a different time range, time range from months ago, data that shouldn't be in the cache because no one query for it for weeks, it is fast as well (it may take 1-2 seconds and not milliseconds, but definitely not 20 seconds).