Re: Table locking problems? - Mailing list pgsql-performance

From Joshua D. Drake
Subject Re: Table locking problems?
Date
Msg-id 42F8F717.6030106@commandprompt.com
Whole thread Raw
In response to Table locking problems?  (Dan Harris <fbsd@drivefaster.net>)
Responses Re: Table locking problems?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
> Could these locking issues be related to the other changes I made?  I'm
> really scared that this is related to choosing XFS, but I sure  hope
> not.   How should I go about troubleshooting the "problem"  queries?
> They don't seem to be specific to a single table or single  database.

My experience is that when this type of thing happens it is typically
specific queries that cause the problem. If you turn on statement
logging you can get the exact queries and debug from there.

Here are some things to look for:

Is it a large table (and thus large indexes) that it is updating?
Is the query using indexes?
Is the query modifying ALOT of rows?

Of course there is also the RTFM of are you analyzing and vacuuming?

Sincerely,

Joshua D. Drake


>
> I'm running 8.0.1 on kernel 2.6.12-3 on 64-bit Opterons if that  matters..
>
>
> -Dan
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>       choose an index scan if your joining column's datatypes do not
>       match


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