Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> wrote: > Implementing index-only scans requires a few changes: I'm happy to see this work! Now that the EXISTS predicates have been optimized to consider semi-join and anti-join techniques, I believe that these index issues (evaluating quals before heap access and skipping heap access when all columns of interest are in an index) are the last significant optimizations missing from PostgreSQL to allow it to outperform our previous DBMS on *all* queries, rather than just the vast majority of them. :-) As far as our production queries go, based on our experience with several other products against this schema, this is the area where the biggest performance gains remain to be realized. -Kevin
-- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
