Re: Very slow delete.

Hi Tom,

Thanks for your help. I checked types and indexes, to no avail. Vacuum
didn't help. but vacuum full did, it's now fast again.

Cheers,

Brock

On Mon, 11 Oct 2004 23:38:49 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Brock Henry <brock.henry@gmail.com> writes:
> > delete from people where id < '2000'
>
> > Index Scan using people_pkey on people  (cost=0.00..71.68 rows=2792
> > width=6) (actual time=1.361..5.657 rows=2000 loops=1)
> >   Index Cond: (id < 3000)
> > Total runtime: 13.006 ms
> > 3 row(s)
> > Total runtime: 63,869.322 ms
>
> So 13 msec to find the rows to delete, and 63850+ msec in overhead.
> Which is certainly from the foreign keys that reference this table,
> because the referencing tables have to be checked to see if they
> contain copies of the key values being deleted.
>
> You either don't have indexes on the referencing columns, or there
> is a datatype mismatch, or possibly you need to update statistics
> for those tables.
>
>                         regards, tom lane
>