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

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...

-mjy