Re: Add RANGE with values and exclusions clauses to the Window Functions

On Tuesday, 30 January 2018, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Another thing I'm a little confused by is the precise API for the in_range
> support functions (the lack of any documentation for it doesn't help).
> I wonder why you chose to provide two support functions per datatype
> combination rather than one with an additional boolean argument.
> In fact, it almost seems like the "end" flag could already do the
> job, though I may be missing something. As-is, it seems like this
> setup involves a lot of duplicate code and catalog entries ... what
> are we gaining from that?
>
> regards, tom lane
>

We could instead remove the "desc" functions and flip the values of both
"preceding" and "end" for a descending order. It just needs an extra bool
in the parsenode/plannode structs to send to nodeWindowAgg.

I used two functions because it seemed cleaner to me to get the Oid of the
function in the parser for both ordering types, so then nodeWindowAgg
doesn't have to know about sort order (doesn't have to have extra
conditionals for the two). But yes it does increase the catalog and code
size so is probably better removed.

I will send out v10 soon with the desc functions removed and the
EXCLUDE_NO_OTHERS define removed.