[mythtv-users] Slow MySQL query after delete

David Rees drees76 at gmail.com
Thu Sep 6 09:26:26 UTC 2007

On 9/5/07, crs23 <pvr at groundhog.pair.com> wrote:
> Yep, I'm still here.  I applied your patch and ran it.  Unfortunately, I'm
> still getting about 30 seconds.  Thanks for trying.  With various
> defragmentations and my.cnf adjustments and running optimize on the DB I
> appear to be down from 36 seconds to 30 seconds, but that's really not good
> enough.  As I mentioned in another post in this thread I think I'll just
> have to remove rows from recordmatch.  I also pointed out that this SELECT
> should be considered a serious bug in MythTV.

I may have missed it, but did you post the version of MySQL and the
relevant parameters from my.cnf that would affect performance?

When the query is running, does it appear that the system is CPU bound
or IO bound (watch vmstat 1 output). If you could grab a snippet of
vmstat 1 output while the query is running that would be helpful. What
are the specs of the machine running MySQL?


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