On 2017-03-23 03:43:57 +0000, Andrew Gierth wrote: > >>>>> "Andres" == Andres Freund <and...@anarazel.de> writes: > > Andres> Changes to advance_aggregates() are, in my experience, quite > Andres> likely to have performance effects. This needs some > Andres> performance tests. > [...] > Andres> Looks like it could all be noise, but it seems worthwhile to > Andres> look into some. > > Trying to sort out signal from noise when dealing with performance > impacts of no more than a few percent is _extremely hard_ these days.
Indeed. But that doesn't mean we needn't try. With some determination and profiling you can often sepearate signal from noise - I managed to track down 0.12% regressions in the expression evaluation work... > I will go ahead and do this, out of sheer curiosity if nothing else, > but the preliminary results suggest there's probably nothing worth > holding up the patch for. Agreed. I'd want to run one more profile, checking whether the profiles indicate new hotspots, but other than that... Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers