Skip site navigation (1) Skip section navigation (2)

Re: Bitmap indexes

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: alex(at)neteconomist(dot)com
Cc: PostgreSQL Perfomance <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Bitmap indexes
Date: 2005-01-28 16:13:46
Message-ID: 2472.1106928826@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-performance
Alex Turner <armtuk(at)gmail(dot)com> writes:
> I was wondering about index types.  Oracle has an index type called a
> 'bitmap' index.

There's a great deal about this in the list archives (probably more in
pgsql-hackers than in -performance).  Most of the current interest has
to do with building in-memory bitmaps on the fly, as a way of decoupling
index and heap scan processing.  Which is not quite what you're talking
about but should be pretty effective for low-cardinality cases.  In
particular it'd allow AND and OR combination of multiple indexes, which
we do poorly or not at all at the moment.

			regards, tom lane

In response to

Responses

pgsql-performance by date

Next:From: Frank WilesDate: 2005-01-28 16:17:24
Subject: Re: PostgreSQL clustering VS MySQL clustering
Previous:From: PFCDate: 2005-01-28 16:04:48
Subject: Re: Bitmap indexes

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group