Re: [HACKERS] Not enough memory for complex join

Oleg Broytmann wrote:
>
> Hi!
>
> On Fri, 5 Mar 1999, Vadim Mikheev wrote:
> > Oleg Broytmann wrote:
> > >
> > > Nested Loop (cost=0.00 size=1 width=18)
> > > -> Nested Loop (cost=0.00 size=1 width=14)
> > > -> Merge Join (cost=0.00 size=1 width=10)
> > > -> Seq Scan (cost=0.00 size=0 width=0)
> > > -> Sort (cost=0.00 size=0 width=0)
> > > -> Seq Scan on districts d (cost=0.00 size=0 width=4)
> > > -> Seq Scan (cost=0.00 size=0 width=0)
> > > -> Sort (cost=0.00 size=0 width=0)
> > > -> Seq Scan on shops sh (cost=0.00 size=0 width=6)
> > > -> Seq Scan on central cn (cost=0.00 size=0 width=4)
> > > -> Seq Scan on positions p (cost=0.00 size=0 width=4)
> > ^^^^^^
> > vacuum...
>
> I didn't think it could be of any help. I have a copy of this database
> on my local computer. I dump db on server and put it on local computer
> every other day, so I thiink VACUUM is unneccessary here.
> Anyway, I tried to VACUUM the db. No, the query didn't execute -
> postgres ate all memory and died.

EXPLAIN after vacuum?

There was MergerJoin before vacuum => 2 sorts, but sorting eats
some memory, this is why I suggested vacuum..

And, btw, please re-post your query/table definition...

Vadim