Re: Experiences of PostgreSQL on-disk bitmap index patch

Thanks Robert!

So you indicate that the so called bitmap index scan, a.k.a in-memory bitmap
indexes (right?), already adds such an improvement when it comes to
optimized response time on large query sets (having the characteristics as
normally used to identify cases where bitmap indexes improves performance
like: low cardinality keys, large data volumes etc), so that the on-disk
indexes are not really needed or atleast not worth wile implementing?

Regards,
Christian

2007/6/25, Robert Treat <xzilla(at)users(dot)sourceforge(dot)net>:
>
> On Thursday 21 June 2007 04:39, Christan Josefsson wrote:
> > Ok.
> >
> > Big thanks for the information.
> >
> > You mentioned Bizgres, do you have any more information in that
> direction,
> > or do you know who to contact regarding information on Bizgres bitmap
> > indexes. If there is a bitmap index patch in Bizgres which can be
> applied
> > to the latest stable source of PostgreSQL then I have a solution until
> 8.4
> > (which I according to your answers is the assumed release for
> introducing
> > on-disk bitmap indexes).
> >
>
> If you really want to see on-disk bitmaps in, you might want to study the
> patches and the missing vacuum related bits and then think about
> submitting
> an updated version. My take on the future of that patch is the original
> developers aren't terribly motivated to finish it, in much part because
> some
> of the testing people have done vs. 8.3 shows it solves an even smaller
> number of issues than originally hoped. my .02 anyway.
>
> --
> Robert Treat
> Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL
>