Andres Freund wrote: > On 2014-08-26 22:19:47 -0400, Tom Lane wrote: > > Andres Freund <and...@2ndquadrant.com> writes:
> > I would say that the issue most deserving of performance testing is your > > sizing of the linear-search array --- it's not obvious that 8 is a good > > size. > > It's about the size of a cacheline on all common architectures, that's > how I found it. I don't think it makes a very big difference whether we > make it 4 or 12, but outside of that range I think it'll be unlikely to > be beneficial. The regression tests never go about three or four pins or > so currently, so I think that's a number unlikely to regularly be > crossed in practice. FWIW scanning a minmax index will keep three pages pinned IIRC (metapage, current revmap page, current regular page). -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers