Horton

Re: Compatible defaults for LEAD/LAG

Vik Fearing <vik@postgresfriends.org>

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From: Vik Fearing <vik@postgresfriends.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2020-05-31T23:30:21Z
Lists: pgsql-hackers 
On 5/31/20 9:53 PM, Tom Lane wrote:
> When the anycompatible patch went in, I thought for a little bit about
> trying to use it with existing built-in functions, but didn't have the
> time to investigate the issue in detail.  I'm not in favor of hacking
> things one-function-at-a-time here; we should look through the whole
> library and see what we've got.

BTW, I did go through pg_proc.dat to see what we've got and these were
the only two I found.  I mentioned that in a part you didn't quote.  Now
I went through again, this time using a query on pg_proc itself, and I
missed array_replace during my manual scan.

array_replace, lead, and lag are the only functions we have that take
more than one anyelement.

There are many functions (seemingly all operator implementations) that
take multiple anyarray, anyrange, and anyenum; but none with anynonarray
and only those three for anyelement.  Are you sure we don't want to give
at least the anycompatible type a nice public workout with this?
-- 
Vik Fearing

Commits

  1. Declare assorted array functions using anycompatible not anyelement.

  2. Declare lead() and lag() using anycompatible not anyelement.