Bug in aggregates in windowing context

Folks,

Elein Mustain mentioned this, and I came up with a short repro.  The
SQL standard does not distinguish between what's available to
aggregates normally and in the windowing context.  However...

SELECT count(DISTINCT i) FROM (VALUES (1),(2),(3),(1)) AS s(i);count 
-------    3
(1 row)

SELECT count(DISTINCT i) OVER () FROM (VALUES (1),(2),(3),(1)) AS s(i);
ERROR:  DISTINCT is not implemented for window functions
LINE 1: SELECT count(DISTINCT i) OVER () FROM (VALUES (1),(2),(3),(1...              ^

I see the error set up in src/backend/parser/parse_func.c, but no real
reasoning why.

Anyhow, I think it's a bug and needs back-patching.

Cheers,
David.
-- 
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
Skype: davidfetter      XMPP: david.fetter@gmail.com

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