Re: FILTER clause for non-aggregate window functions

I could not put the restrictions in WHERE because I want them to be applied
only to the window frame, not to all selected rows.

On 12 Dec. 2017 18:35, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> =?UTF-8?B?0JDQvdC00YDQtdC5INCW0LjQtNC10L3QutC+0LI=?= <pensnarik(at)gmail(dot)com>
> writes:
> > Why FILTER is not implemented for non-aggregate functions?
>
> The SQL standard only describes FILTER for aggregates. I'm not sure
> offhand whether it'd be semantically sensible for window functions.
> In any case, seems like most of the cases where you'd want it can be
> expressed equally well by putting the restriction into WHERE.
>
> regards, tom lane
>