Re: [HACKERS] Bug on complex join

Oleg Broytmann wrote:
>
> Hi!
>
> On Tue, 9 Mar 1999, Hannu Krosing wrote:
> > > SELECT cn.date_i, cn.pos_id
> > > FROM central cn
> > > WHERE cn.date_i >= current_date - '300 days'::timespan
> > >
> > > returns 3156 rows. But this:
> > >
> > > SELECT cn.date_i, p.subsec_id, cn.pos_id, p.pos_id
> > > FROM central cn, shops sh, districts d, positions p
> > > WHERE cn.date_i >= current_date - '300 days'::timespan
> >
> > this should return
> > 3156 * count(shops) * count(districts) * count(positions)
> >
> > which is probably too much for the backend ;(
^^^^^^^^^^^^^^^
For the client-side, not for the backend - backend doesn't
keep all result tuples in memory.

>
> Bad news. Thanks for pointing this.

Vadim