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.