MySQL Forums
Forum List  »  MyISAM

Re: Problems with system locking
Posted by: Ingo Strüwing
Date: May 02, 2006 10:46AM

Brian O'Donnell wrote:
...
> If system locks are indicated in SHOW
> PROCESSLIST when the system is flushing its key
> cache, and there are multiple threads trying to
> write to the same table (as is the case in our
> setup) then are they explained as contentions
> between the various INSERT statements?

Yes. This is my opinion.

> ie: one
> INSERT ends and starts flushing the key cache but
> while that happens, the next INSERT is trying to
> execute but can't because the key cache is being
> flushed???

Exactly.

> However if this is the case, I still
> don't see why the locks should cause a significant
> degradation in performance, which appears to be
> the case.

I agree. This looks odd.

> Anyway, here are the output traces from
> myisamchk...

I agree that the maximum table size is big enough for you. There should be no size problems for you. Also I don't see other possible problems with it.

Did I mention the option to use MERGE tables to you? Regularily adding a new table "at the end" and dropping the front table?

Regards

Ingo Strüwing, Senior Software Developer - Storage Engines
MySQL AB, www.mysql.com

Options: ReplyQuote


Subject
Views
Written By
Posted
8965
April 26, 2006 05:37AM
9573
April 27, 2006 04:36AM
Re: Problems with system locking
2833
May 02, 2006 10:46AM
3869
June 13, 2006 09:59PM
2770
June 14, 2006 10:22AM
3008
June 15, 2006 11:18AM
2892
July 14, 2006 03:52PM
2818
August 22, 2006 11:34AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.