On Thu, Feb 25, 2016 at 1:43 PM, Bruce Momjian <br...@momjian.us> wrote: > On Thu, Feb 25, 2016 at 12:50:06PM +1300, Thomas Munro wrote: >> On Thu, Feb 25, 2016 at 12:26 PM, Bruce Momjian <br...@momjian.us> wrote: >> > On Thu, Feb 25, 2016 at 10:06:34AM +1100, James Sewell wrote: >> >> Now when I run the following SQL (multiple times to allow for getting >> >> everything into shared buffers, which is 4GB on my machine): >> >> >> >> >> >> select sum(count_n) from base group by view_time_day; >> >> >> >> >> >> I get the following results: >> >> >> >> >> >> PSQL 9.5 - ~21 seconds >> >> PSQL 9.6 devel - ~8.5 seconds >> >> >> >> >> >> I think that's pretty good! >> >> >> >> I know this is a devel release, things may change, blah blah. But still, >> >> something has changed for the better here! >> > >> > Wow, that is cool. Can anyone suggest which commit improved this? >> >> Since it sums numerics, maybe integer transition functions from commit >> 959277a4f579da5243968c750069570a58e92b38 helped? > > Seems it was a wrong report, but anyway, this commit was in 9.5, while > the user reported a speedup in 9.6.
Oops, right, and as David said it's also irrelevant. FWIW I couldn't reproduce this comparing 9.5 with 9.6, but the numbers reported just happen to match nearly exactly what I get comparing -O2 and -O0 builds here... -- Thomas Munro http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
