That's interesting.  So if you have a composite index on two columns, is
there much of a reason (usually) to create single indexes on each of the
two columns?  I guess the single indexes might be slightly faster
depending on the number of different values/combinations, so probably
"it depends" eh?  


On Fri, 19 Jan 2007 16:57:42 -0600, "Ron Johnson"
<[EMAIL PROTECTED]> said:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On 01/19/07 15:53, Jan Muszynski wrote:
> > Rather simple question, of which I'm not sure of the answer.
> > 
> > If I have a multiple column index, say:
> >     Index index1 on tableA (foo,bar)
> > 
> > and I then:
> >     Select * from "tableA" where foo = <some value>
> > 
> > Will index1 be used, or am I looking at a seqscan in all circumstances?
> 
> Yes, it will use the index.
> 
> However, in earlier versions, the lvalue & rvalue needed to match in
> type to use the index.
> 
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.6 (GNU/Linux)
> 
> iD8DBQFFsUzmS9HxQb37XmcRArY8AKDqzS5FeY1HwkSGeOlhQsjsdpAV5gCghiWj
> R4e7rBWaAAGF25ZFhy1Elgc=
> =Wkp8
> -----END PGP SIGNATURE-----
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 1: if posting/reading through Usenet, please send an appropriate
>        subscribe-nomail command to [EMAIL PROTECTED] so that your
>        message can get through to the mailing list cleanly

---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?

               http://www.postgresql.org/docs/faq

Reply via email to