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

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От Andrew Gierth
Тема Re: [BUGS] Improper const-evaluation of HAVING with grouping sets and subquery pullup
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Msg-id 87lgkclh7t.fsf@news-spur.riddles.org.uk
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Ответ на Re: [BUGS] Improper const-evaluation of HAVING with grouping sets and subquery pullup  (Tom Lane <tgl@sss.pgh.pa.us>)
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>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:
Tom> One thing I'm wondering is why only the HAVING clause would beTom> subject to the problem. I'm a bit surprised
thatthe "x" in theTom> targetlist didn't become a constant as well. This may be pointingTom> to some klugery in the
GROUPINGSETS patch that we could clean upTom> if we use placeholders for this.
 

This shows that the problem can extend to the targetlist too:

select four, x || 'x' from (select four, ten, 'foo'::text as x from tenk1 ) as tgroup by grouping sets(four, x);
four | ?column? 
------+----------   3 | foox   0 | foox   1 | foox   2 | foox     | foox
(5 rows)

What seems to happen in the original case is that the 'foo' constant
ends up in the projection of the input to the aggregate node, with a Var
in the output.

-- 
Andrew (irc:RhodiumToad)


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