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