Re: WIP Patch for GROUPING SETS phase 1

On Thu, Aug 21, 2014 at 11:01 AM, Andrew Gierth
<andrew(at)tao11(dot)riddles(dot)org(dot)uk> wrote:
>>>>>> "Heikki" == Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> writes:
> Heikki> Uh, that's ugly. The EXPLAIN out I mean; as an implementation
> Heikki> detail chaining the nodes might be reasonable. But the above
> Heikki> gets unreadable if you have more than a few grouping sets.
>
> It's good for highlighting performance issues in EXPLAIN, too.

Perhaps so, but that doesn't take away from Heikki's point: it's still
ugly. I don't understand why the sorts can't all be nested under the
GroupAggregate nodes. We have a number of nodes already (e.g. Append)
that support an arbitrary number of children, and I don't see why we
can't do the same thing here.

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