On 2016-07-14 20:41:21 -0700, Peter Geoghegan wrote: > On Wed, Jul 13, 2016 at 8:06 PM, Andres Freund <and...@anarazel.de> wrote: > > I've quickly hacked up an alternative linear addressing hashtable > > implementation. And the improvements are quite remarkable. > > > > Example Query: > > EXPLAIN ANALYZE SELECT SUM(l_extendedprice) FROM lineitem WHERE (l_shipdate > > >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date); > > > timing without analyze: 4136.425 4101.873 4177.441 > > > > after: > > > timing without analyze: 2647.364 2674.456 2680.197 > > > > as you can see the the time for the bitmap index scan goes from 2461.622 > > to 952.161. > > That's pretty great. I wonder what this would look like with a BRIN > index, since l_shipdate looks like a good candidate for BRIN indexing.
Brin indexes IIRC always end up using tidbitmap.c, so the benefits should be there as well ;) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
