Re: Window function with valued based range frames? - Mailing list pgsql-general

From Tom Lane
Subject Re: Window function with valued based range frames?
Date
Msg-id 19402.1411787063@sss.pgh.pa.us
Whole thread Raw
In response to Window function with valued based range frames?  (David G Johnston <david.g.johnston@gmail.com>)
List pgsql-general
David G Johnston <david.g.johnston@gmail.com> writes:
> Just looking for recollection regarding why these were omitted initially and
> if anyone has concerned adding them in follow-up.

My recollection is that RANGE requires some data-type-specific behavior
that we don't have any provision for in PG's datatype extension framework
(something about increment/decrement I think, but too lazy to consult the
archives for details).  The original window-function patch had some klugy
hard-wired behavior for a small set of datatypes, which we quite properly
rejected as not being up to project standards: datatype extensibility is
one of PG's defining features, and we're not going to give it up lightly.
Nobody's yet done the work to get something that would pass muster.

> With the recent
> hypothetical work being done maybe these can be re-evaluated in a fresh
> light?

AFAIK those functions are unrelated to this problem.

            regards, tom lane


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