Re: increase index performance

On Thu, 14 May 2009, Ow Mun Heng wrote:
> Shouldn't BITMAP indexes come into play?
>
> Does having one index w/ 3 parameters being better than 3 index w/ 3
> different parameters be better for BITMAP index seeks?

I'll let someone correct me if I'm wrong, but using a single index that
exactly covers your search is always going to be better than munging
together results from several indexes, even if the planner decides to turn
it into a bitmap index scan (which will be more likely in PG8.4 with
effective_concurrency set).

Matthew

--
 I don't want the truth. I want something I can tell parliament!
                                              -- Rt. Hon. Jim Hacker MP