Re: Combining Aggregates

On Wed, Mar 16, 2016 at 8:34 AM, David Rowley
<david(dot)rowley(at)2ndquadrant(dot)com> wrote:
> On 16 March 2016 at 06:39, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
>> After looking at the parallel aggregate patch, I also looked at this one, as
>> it's naturally related. Sadly I haven't found any issue that I could nag
>> about ;-) The patch seems well baked, as it was in the oven for quite a long
>> time already.
>
> Thanks for looking at this.
>
>> The one concern I do have is that it only adds (de)serialize functions for
>> SUM(numeric) and AVG(numeric). I think it's reasonable not to include that
>> into the patch, but it will look a bit silly if that's all that gets into
>> 9.6.
>
> Yes me too, so I spent several hours yesterday writing all of the
> combine functions and serialisation/deserialisation that are required
> for all of SUM(), AVG() STDDEV*(). I also noticed that I had missed
> using some existing functions for bool_and() and bool_or() so I added
> those to pg_aggregate.h. I'm just chasing down a crash bug on
> HAVE_INT128 enabled builds, so should be posting a patch quite soon. I
> didn't touch the FLOAT4 and FLOAT8 aggregates as I believe Haribabu
> has a patch for that over on the parallel aggregate thread. I've not
> looked at it in detail yet.

The additional combine function patch that I posted handles all float4 and
float8 aggregates. There is an OID conflict with the latest source code,
I will update the patch and post it in that thread.

Regards,
Hari Babu
Fujitsu Australia