Gianni,
> me and Gabriele Bartolini have been working on Bitmap Indexes (BMI) in
> the last weeks, with advice and guidance from Simon Riggs. We feel
> that we are about to approach the point where it is appropriate to ask
> for feedback from this list.
The other major issue with the Bitmap index patch as it stood in 2007 was
that performance just wasn't that much faster than a btree, except for
specific corner cases. Otherwise, someone else would have been interested
enough to pick it up and finish it.
So performance testing of the patch is absolutely essential.
--
--Josh
Josh Berkus
PostgreSQL
San Francisco