Thread: Re: Strange query plan

Re: Strange query plan

From
Tom Lane
Date:
Oleg Bartunov <oleg@sai.msu.su> writes:
> The best plan I've got eliminating  IN predicate:
> select msg_prt.tid as mid from msg_prt
>  where exists (select idx.tid from idx where msg_prt.tid=idx.tid
>                and idx.did=1 and idx.lid = 1207 and idx.lid=59587 )

Surely that returns zero rows?
        regards, tom lane


Re: Strange query plan

From
Oleg Bartunov
Date:
On Tue, 5 Jun 2001, Tom Lane wrote:

> Oleg Bartunov <oleg@sai.msu.su> writes:
> > The best plan I've got eliminating  IN predicate:
> > select msg_prt.tid as mid from msg_prt
> >  where exists (select idx.tid from idx where msg_prt.tid=idx.tid
> >                and idx.did=1 and idx.lid = 1207 and idx.lid=59587 )
>
> Surely that returns zero rows?
>

Oops, sorry :-)
should be
select msg_prt.tid as mid from msg_prtwhere exists (select idx.tid from idx where msg_prt.tid=idx.tid              and
idx.did=1and ( idx.lid = 1207 or idx.lid=59587 ));
 

but this is not a big win.

Anyway, what's about original query ?



>             regards, tom lane
>
Regards,    Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83