On 25 February 2016 at 12:50, Thomas Munro
<thomas.munro@enterprisedb.com> 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:
>>> 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?
Those changes were only really to allow bigint to use int128
internally instead of NUMERIC, it didn't make any changes to any
NUMERIC aggregate functions.
It would be interesting to see the explain analyze buffers for both.
Perhaps 9.5 just read more buffers from disk than 9.6 did.
-- David Rowley http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services