Re: [PERFORM] Seq scan of table?

From: Bjørn T Johansen <btj(at)havleik(dot)no>
To: pgsql-general(at)postgresql(dot)org, pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] Seq scan of table?
Date: 2003-09-05 13:23:24
Message-ID: 1062768204.11199.23.camel@pennywise.havleik.no
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On Fri, 2003-09-05 at 12:07, Richard Huxton wrote:
> On Friday 05 September 2003 09:47, Bjorn T Johansen wrote:
> > I think I have found out why.. I have a where clause on a ID field but it
> > seems like I need to cast this integer to the same integer as the field is
> > defined in the table, else it will do a tablescan.
> >
> > Is this assumtion correct? And if it is, do I then need to change all my
> > sql's to cast the where clause where I just have a number (eg where field
> > = 1) to force the planner to use index scan instead of seq scan?
>
> PG's parser will assume an explicit number is an int4 - if you need an int8
> etc you'll need to cast it, yes.
> You should find plenty of discussion of why in the archives, but the short
> reason is that PG's type structure is quite flexible which means it can't
> afford to make too many assumptions.

Oki, I am using both int2 and int8 as well, so that explains it...
Thanks!

BTJ

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