5 ms·
Yep, this is a big deal, for me at least. It basically makes it almost cost-free to add indexes to tables that are write heavy. I've always felt like Bitmap In
by saosebastiao 11y ago
Yep, this is a big deal, for me at least. It basically makes it almost cost-free to add indexes to tables that are write heavy.
I've always felt like Bitmap Indexes were a killer feature, and never understood why they weren't used more in databases. If you have a low cardinality column (anything suitable for an enum), your indexes become incredibly fast and cheap.
- pjungwir 11y agoThere was an effort to build bitmap indexes for Postgres a few years ago. There are details in the mailing list archives. It looks like it was almost completed! It's high on my list of things to tackle if I ever get time to start contributing, but maybe someone else will get to it first.
- facetube 11y agoIs that different than the bitmap index access method, which IIRC landed in 8.1 or so, and is used to combine results of multiple index scans?
- pjungwir 11y agoYes, totally different thing. :-) A great book on query plan stuff is here: http://www.amazon.com/PostgreSQL-High-Performance-Gregory-Smith/dp/184951030X http://www.amazon.com/PostgreSQL-High-Performance-Gregory-Sm...