Re: Improper const-evaluation of HAVING with grouping sets and subquery pullup

>>>>> "Tom" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

>> I propose the attached patch to fix that. It forces the use of
>> PlaceHolderVars in subquery pullup, if the parent query has grouping
>> sets and HAVING. I'm not 100% sure that's the right approach or a
>> misuse of the placeholder system, so comments welcome.

I've been testing Heikki's patch with the havingQual condition removed,
and I haven't found any issues yet.

Tom> One thing I'm wondering is why only the HAVING clause would be
Tom> subject to the problem. I'm a bit surprised that the "x" in the
Tom> targetlist didn't become a constant as well. This may be pointing
Tom> to some klugery in the GROUPING SETS patch that we could clean up
Tom> if we use placeholders for this.

As far as I can tell, the "x" _does_ become a constant, but then in
setrefs, because it's still labelled with a sortgroupref, it gets
replaced by a Var again. I don't recall touching any of that in the GS
work, because it was already like that for plain GROUP BY.

--
Andrew (irc:RhodiumToad)