On Thu, Dec 10, 2015 at 4:55 AM, Andreas Seltenreich <seltenre...@gmx.de> wrote: > Tom Lane writes: > >> Merlin Moncure <mmonc...@gmail.com> writes: >>> Aside from the functional issues, could your changes result in >>> performance regressions? > [...] >> It's a little bit harder to gauge the impact on planner speed. The >> transitive closure calculation could be expensive in a query with many >> lateral references, but that doesn't seem likely to be common; and anyway >> we'll buy back some of that cost due to simpler tests later. I'm >> optimistic that we'll come out ahead in HEAD/9.5 after the removal >> of LateralJoinInfo setup. It might be roughly a wash in the back >> branches. > > On the empirical side: I see a speedup of 0.4% in testing speed with the > patch applied. It could very well be me venting the room one additional > time during the second session, resulting in the CPUs spending more time > in their opportunistic frequency range or something.
Really...wow. That satisfies me. You ought to be commended for sqlsmith -- great stuff. merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
