Re: [HACKERS] Partition-wise aggregation/grouping

On Thu, Mar 8, 2018 at 7:49 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Thu, Mar 8, 2018 at 9:15 AM, Jeevan Chalke
> <jeevan(dot)chalke(at)enterprisedb(dot)com> wrote:
> > I am not sure why we don't set reltarget into the grouped_rel too.
> >
> > But if we do so like we did in partially_grouped_rel, then it will be lot
> > easier for partitionwise aggregate as then we don't have to pass target
> to
> > functions creating paths like create_append_path. We now need to update
> > generate_gather_paths() to take target too as it is now being called on
> > grouped_rel in which reltarget is not set.
> >
> > But yes, if there is any specific reason we can't do so, then I think the
> > same like Ashutosh Said. I didn't aware of such reason though.
>
> I see no problem with setting reltarget for the grouped_rel. Before
> we added partially_grouped_rel, that rel computed paths with two
> different targets: partial paths had the partial grouping target, and
> non-partial paths had the ordinary grouping target. But that's fixed
> now.
>

OK.
Will update my changes accordingly.
If we set reltarget into the grouped_rel now, then I don't need one of the
refactoring patch which is passing target to the path creation functions.

> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>

--
Jeevan Chalke
Technical Architect, Product Development
EnterpriseDB Corporation
The Enterprise PostgreSQL Company