On Fri, Oct 16, 2015 at 11:43:10AM -0300, Alvaro Herrera wrote:
> Bruce Momjian wrote:
>
> > Probably the most controvertial change was to move on-disk bitmap
> > indexes to the "not wanted" section, though I kept the links in case we
> > change our minds. I just can't see how they would be a win with GIN and
> > in-memory bitmaps.
>
> Yeah, I recall we discussed bitmap indexes a lot and we found there
> wasn't a lot of room to use them because GIN is just too good, it seems.
> Also, the patches that were developed had a number of issues. Anyone
> wanting to develop bitmap indexes would probably be better off starting
> from scratch.
Yes, that was my conclusion too. We have played with the on-disk bitmap
idea for a long time, but GIN has gotten very good in that time.
Are you suggesting I remove those links? It is kind of odd to have
links to patches for features we don't want, or just keep it?
> > (I don't think BRIN indexes help for on-disk bitmap use-cases, do
> > they?)
>
> No, they don't. I expect BRIN to be very bad in a limited domain (which
> is where bitmap indexes are supposed to shine), except under specific
> conditions.
Yes, that was my conclusion too. Thanks.
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://enterprisedb.com
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