From: | Bill Huff <bhuff(at)colltech(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Poor Delete performance |
Date: | 2001-03-12 06:32:33 |
Message-ID: | 20010312003233.G2483@colltech.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
I am having some performance issues with deletion.
It appears that in deleting records from a table with a significant
number or rows ( in this case 1.3 million ) it takes about 1 hour per
100K rows deleted if deleting more then 400K at a time. This sounds
way to slow to me. If I break it up into smaller deletes then I can
usually get about 5K rows per minute, but even that seems awfully slow
to me.
The machine is a pretty beefy box ( PIII 800Mhz, 256M, SCSI III )
and is basically doing nothing else. When performing the delete the
system goes to 100% utilization ( >95% is postmaster ) and stays that
way until the delete finishes. My guess is that the overhead of MVCC
tracking all of the rows deleted so that a rollback can be performed
is killing me here, but I can see no way to get around it.
I have searched the on-line archives for all the postgres lists and
checked the FAQ and I can't find anything that gives any insight into
increasing delete performance.
Any information whatsoever would be greatly appreciated.
--
Bill
--
_____
/ ___/___ | Bill Huff / bhuff(at)colltech(dot)com
/ /__ __/ | Voice: (512) 263-0770 x 262
/ /__/ / | Fax: (512) 263-8921
\___/ /ollective | Pager: 1-800-946-4646 # 1406217
\/echnologies |------[ http://www.colltech.com ] ------
From | Date | Subject | |
---|---|---|---|
Next Message | martin.chantler | 2001-03-12 09:59:09 | Re: Re: Anyone can create tables! |
Previous Message | David Wall | 2001-03-12 02:12:29 | Re: Data type for storing images? |