Re: Random note of encouragement - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Random note of encouragement
Date
Msg-id 20160225004357.GB14651@momjian.us
Whole thread Raw
In response to Re: Random note of encouragement  (Thomas Munro <thomas.munro@enterprisedb.com>)
Responses Re: Random note of encouragement
List pgsql-hackers
On Thu, Feb 25, 2016 at 12:50:06PM +1300, Thomas Munro wrote:
> On Thu, Feb 25, 2016 at 12:26 PM, Bruce Momjian <bruce@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.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com

+ As you are, so once was I. As I am, so you will be. +
+ Roman grave inscription                             +



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