Re: Table locking problems?

On Tue, Aug 09, 2005 at 12:04:11PM -0600, Dan Harris wrote:
> These changes have definitely improved performance, but I am now
> finding some trouble with UPDATE or DELETE queries "hanging" and
> never releasing their locks.  As this happens, other statements queue
> up behind it.

Have you examined pg_locks to see if the UPDATE or DELETE is blocked
because of a lock another session holds?

Are you using foreign keys?  When updating referencing rows, released
versions of PostgreSQL acquire a lock on the referenced row that can
hurt concurrency or cause deadlock (this will be improved in 8.1).

--
Michael Fuhr