Re: 1-/2-dimensional indexes for common columns, rationale?

am  Wed, dem 26.03.2008, um 16:15:20 +0100 mailte Marinos Yannikos folgendes:
> A. Kretschmer schrieb:
> >>create index foo1 on bla (a);
> >>create index foo2 on bla (b);
> >>create index foo3 on bla (a,b);
> >>[...]
> >
> >Which version do you have? Since 8.1 pg can use a so called 'bitmap
> >index scan', because of this feature i guess you don't need the index
> >foo3. (if you have 8.1 or higher)
>
> 8.3.1 - foo3 is being used though in presence of both foo1 and foo2, so
> I'd suppose that it's a better choice even with bitmap index scan
> available...

Maybe...


Andreas
--
Andreas Kretschmer
Kontakt:  Heynitz: 035242/47150,   D1: 0160/7141639 (mehr: -> Header)
GnuPG-ID:   0x3FFF606C, privat 0x7F4584DA   http://wwwkeys.de.pgp.net