Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrew Gierth <andrew@tao11.riddles.org.uk>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Pg Bugs <pgsql-bugs@postgresql.org>
Date: 2017-10-16T15:15:18Z
Lists: pgsql-bugs 
Andrew Gierth <andrew@tao11.riddles.org.uk> writes:
> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:
>  Tom> Uh ... but I thought the point here is that the outputs aren't
>  Tom> really constant in the presence of grouping sets.

> select x, y, sum(z) from (select 1 as x, 2 as y, 3 as z) s
>  group by grouping sets (x,y);

> x and y aren't constants, but z is.

OK, but that just means we should put PHV wrapping around only the
grouping-set columns.

BTW, also need to think about GS expressions, eg

select x+y, sum(z) from (select 1 as x, 2 as y, 3 as z) s
 group by grouping sets (x+y);

Not real sure what needs to happen here.

			regards, tom lane

Commits

  1. Fix incorrect handling of subquery pullup in the presence of grouping sets.

  2. Make setrefs.c match by ressortgroupref even for plain Vars.

  3. Make the upper part of the planner work by generating and comparing Paths.