Re: Parallel Aggregate

On 16 March 2016 at 11:00, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> I don't see why we would need to leave aggpartial out of the equals()
> check. I must be missing something.

See fix_combine_agg_expr_mutator()

This piece of code:

/*
* Aggrefs for partial aggregates are wrapped up in a PartialAggref,
* we need to look into the PartialAggref to find the Aggref within.
*/
foreach(lc, context->subplan_itlist->tlist)
{
PartialAggref *paggref;
tle = (TargetEntry *) lfirst(lc);
paggref = (PartialAggref *) tle->expr;

if (IsA(paggref, PartialAggref) &&
equal(paggref->aggref, aggref))
break;
}

if equals() compared the aggpartial then this code would fail to find
the Aggref in the subnode due to the aggpartial field being true on
one and false on the other Aggref.

--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services