On Mon, May 21, 2018 at 4:34 PM, David Rowley <david.row...@2ndquadrant.com> wrote: > On 19 May 2018 at 03:58, Amit Langote <amitlangot...@gmail.com> wrote: >> I wonder what you think about including this little performance item: >> >> https://www.postgresql.org/message-id/e1eotsq-0005v0...@gemulon.postgresql.org >> >> especially considering the part of the commit message which states >> >> ...Still, testing shows >> that this makes single-row inserts significantly faster on a table >> with many partitions without harming the bulk-insert case. >> >> I recall seeing those inserts being as much as 2x faster as partition >> count grows beyond hundreds. One might argue that we should think >> about publicizing this only after we've dealt with the >> lock-all-partitions issue that's also mentioned in the commit message >> which is still a significant portion of the time spent and I'm totally >> fine with that. > > While I do think that was a good change, I do think there's much still > left to do to speed up usage of partitioned tables with many > partitions. > > I've been working a bit in this area over the past few weeks and with > PG11 I measured a single INSERT into a 10k RANGE partitioned table at > just 84 tps (!), while inserting the same row into a non-partitioned > table was about 11.1k tps. I have patches locally that take this up to > ~9.8k tps, which I'll submit for PG12. I'm unsure if we should be > shouting anything from the rooftops about the work done in this area > for PG11, since it's still got a long way to go still before the > feature is usable with higher numbers of partitions. I do think your > change was a good one to make, but I just don't want users to think > that we're done here when we all know that much work remains. > > If we're going to add an item in the release notes about this then I > wouldn't object, providing it could be done in a way that indicates > we've not finished here yet, but if that's the case then maybe it's > better to say nothing at all.
You're right, it surely isn't time yet to make fanfare about this. I will look forward to being able to review your patches. :-) Thanks, Amit