Re: Poor Delete performance

As an outside chance, does the table in question have any constraints
defined on it?

On Mon, 12 Mar 2001, Bill Huff wrote:

> 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.