Re: Support for RANGE ... PRECEDING windows in OVER

I am currently looking into this feature. However, as I am quite new to
Postgres, I think it might take me a while to get up to speed. Anyways,
I would also appreciate another round of discussion on the future of the
windowing functions.

Ian Link

> Craig Ringer <mailto:craig(at)2ndquadrant(dot)com>
> Thursday, June 20, 2013 7:24 PM
> Hi all
>
> Since 8.4, PostgreSQL has had extremely useful window function support -
> but support for "RANGE PRECEDING / FOLLOWING" windows was dropped late
> in 8.4's development in order to get the rest of the feature in, per
> http://archives.postgresql.org/pgsql-hackers/2010-02/msg00540.php.
>
> It looks like there was discussion of requiring a new opclass to be
> declared for types or otherwise extending opclasses to provide the
> information required for RANGE ... PRECEDING / FOLLOWING (
> http://www.postgresql.org/message-id/20100211201444.GA28270@svana.org )
> . I can't find any sign that it went anywhere beyond some broad
> discussion:
> http://www.postgresql.org/message-id/13993.1265920013@sss.pgh.pa.us at
> the time.
>
> I've missed this feature more than once, and am curious about whether
> any more recent changes may have made it cleaner to tackle this, or
> whether consensus can be formed on adding the new entries to btree's
> opclass to avoid the undesirable explicit lookups of the '+' and '-'
> oprators.
>
> Some question seems to remain open about how ranges over
> timestamps/intervals should work, but this wasn't elaborated on.
>
> There's been interest in this, eg:
>
> http://pgsql.hackers.free-usenet.eu/[HACKERS]-range-intervals-in-window-function-frames_T66085695_S1
>
> http://grokbase.com/t/postgresql/pgsql-general/105a89gm2n/postgresql-9-0-support-for-range-value-preceding-window-functions
>
>
>