Re: Why is it not using an index?

It should be. I think the response you'll get from the people on this list
is that they're happy to accept a patch...

Greg

----- Original Message -----
From: "Jean-Luc Lachance" <jllachan@nsd.ca>
To: "Gregory Wood" <gregw@com-stock.com>
Cc: "Dmitry Tkach" <dmitry@openratings.com>; "PostgreSQL-General"
<pgsql-general@postgresql.org>
Sent: Friday, March 15, 2002 3:25 PM
Subject: Re: [GENERAL] Why is it not using an index?


> Really, the PostgreSQL interpreter should be smart enough to figure this
> out by itself...
>
>
> Gregory Wood wrote:
> >
> > > explain select * from a where x=3;
> >
> > PostgreSQL is treating 3 as an int4 (integer) type, whereas x is an int2
> > (smallint) type. Try casting the constant as a smallint and it should
use
> > the index:
> >
> > explain select * from a where x=3::smallint;
> >
> > Greg
> >
> > ----- Original Message -----
> > From: "Dmitry Tkach" <dmitry@openratings.com>
> > To: <pgsql-general@postgresql.org.pgsql-sql@postgresql.org>
> > Sent: Friday, March 15, 2002 2:07 PM
> > Subject: [GENERAL] Why is it not using an index?
> >
> > > This must be really simple, but I just can't get it :-(
> > > I have a table (a) with a single column (x):
> > >
> > >            Table "a"
> > >   Attribute |   Type   | Modifier
> > > -----------+----------+----------
> > >   x         | smallint |
> > > Index: a_idx
> > >
> > >
> > >     Index "a_idx"
> > >   Attribute |   Type
> > > -----------+----------
> > >   x         | smallint
> > > btree
> > >
> > > The table has 10000000 rows....
> > >
> > > Now, how come, when I do:
> > >
> > > explain select * from a where x=3;
> > >
> > > it says:
> > >
> > > Seq Scan on bset  (cost=100000000.00..100175934.05 rows=303 width=2)
> > >
> > > Why is it not using a_idx???
> > >
> > > I even tried set enable_seqscan to off - makes no difference :-(
> > >
> > > Any idea what is going on?
> > >
> > > Thanks a lot!
> > >
> > > Dima
> > >
> > >
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