Hello

We are doing some performance tests and would like to disable the cache.
We did set the query_cache_size=0 but it did not have any effect as well
as a "select no_cache". The process is a select on MyISAM table. We are
using a Mysql 5.0.27.

We are wondering if Mysql uses a file to cache or something like this.
The first request take several seconds but the second is instantaneous.
Even if we stop Mysql it does the second one very fast. It is quite odd.
Any clue?

Thank you for your
Johanne

At 9:01 AM -0500 12/21/07, Duhaime Johanne wrote:
>Hello
>
>We are doing some performance tests and would like to disable the cache.
>We did set the query_cache_size=0 but it did not have any effect as well
>as a "select no_cache". The process is a select on MyISAM table. We are
>using a Mysql 5.0.27.
>
>We are wondering if Mysql uses a file to cache or something like this.
>The first request take several seconds but the second is instantaneous.
>Even if we stop Mysql it does the second one very fast. It is quite odd.
>Any clue?
>

You might be seeing the effect of filesystem caching even when the
MySQL query cache is disabled.

--
Paul DuBois, MySQL Documentation Team
Madison, Wisconsin, USA
MySQL AB, www.mysql.com