Re: Bug Fix: COLLATE with multiple ORDER BYs in aggregates

On Thu, Apr 25, 2013 at 06:04:10PM -0400, Tom Lane wrote:
> Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> > On 2013-04-25 13:42:32 -0400, Tom Lane wrote:
> >> The argument for it seems to be that
> >> array_agg(a COLLATE "C" ORDER BY b COLLATE "POSIX")
> >> should not throw an error, but why not?
>
> > Uh. Why should it? SELECT foo COLLATE "C" FROM ... ORDER BY bar COLLATE
> > "POSIX" doesn't throw one either?
>
> After thinking about it a bit more, this case *should* throw an error:
>
> string_agg(a COLLATE "C", b COLLATE "POSIX")
>
> but these should not:
>
> array_agg(a COLLATE "C" ORDER BY b COLLATE "POSIX")
>
> array_agg(a ORDER BY b COLLATE "C", c COLLATE "POSIX")
>
> that is, the ORDER BY expression(s) ought to be considered independently
> rather than as part of the agg's argument list.
>
> It looks like the proposed patch gets this right, but the proposed
> test cases really fail to illuminate the problem IMO.
>
> regards, tom lane

Am I understanding correctly that you want the code left alone and the
test case expanded as above?

Cheers,
David.
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