Re: TODO items for window functions

On Wed, Dec 31, 2008 at 11:04:41AM -0500, Tom Lane wrote:
> Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> > Heikki Linnakangas escribi:
> >> Tom Lane wrote:
> >>> pg_catalog | nth_value | anyelement | anyelement, integer OVER window
> >>
> >> That looks like "OVER window" is associated with the "integer", like
> >> DEFAULT. I don't have any better suggestions, though.
>
> > pg_catalog | nth_value | anyelement | (anyelement, integer) OVER window
>
> Yeah, I had considered that too, and it has a distinct advantage for
> parameterless functions like rank():
>
> Schema | Name | Result data type | Argument data types
> ------------+------+------------------+---------------------
> pg_catalog | rank | bigint | OVER window
> pg_catalog | rank | bigint | () OVER window
>
> The latter is definitely clearer about what you're supposed to do.

+1 on the latter.

> However, it seems kind of inconsistent to do this for window functions
> unless we also make \df start putting parens around the argument lists
> for regular functions. Comments?

Would parens around all the argument lists really be so bad? I'm
thinking not.

Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
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