From: | Vadim Mikheev <vadim(at)krs(dot)ru> |
---|---|
To: | Andreas Zeugswetter <andreas(dot)zeugswetter(at)telecom(dot)at>, Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>, PostgreSQL-development <hackers(at)postgreSQL(dot)org> |
Subject: | Re: AW: [HACKERS] OR clause status report |
Date: | 1998-07-31 14:02:59 |
Message-ID: | 35C1CE93.E744800B@krs.ru |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Vadim Mikheev wrote:
>
> Andreas Zeugswetter wrote:
> >
> > Vadim wrote:
> > >Bruce Momjian wrote:
> > >>
> > >> I have succeeded in making OR clauses use indexes. I have not dealt
> > >> with some of the more complex issues like x=3 or y=5 as Vadim mentioned,
> > >> but at least it works.
> > >>
> > >> test=> select * from test where x=102532 or x=102533;
> > >
> > >But did you care about the case when two indices (on test(x) and
> > >on test(y)) exist ?
> >
> > Do you mean using two indices in one access plan,
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> This.
Actually, I meant NOT USING indices if both exist, because of
currently there is no check that tuples returned by second index
were not returned by first.
> > or the decision which index to use ?
Either both indices should be used or no one...
Also, Bruce, did you test the case (x = 5 or x > 4) ?
What about (x = 5 or x = 5)? - I'm not sure does cnfify()
get rid of duplicates or not...
Vadim
From | Date | Subject | |
---|---|---|---|
Next Message | Vince Vielhaber | 1998-07-31 14:05:14 | Re: [HACKERS] OR clause status report |
Previous Message | Vadim Mikheev | 1998-07-31 13:46:28 | Re: [HACKERS] OR clause status report |