From: Andrew Dunstan <andrew@dunslane.net>
Subject: Re: pgsql: Declare assorted array functions using anycompatible not
 anyelem
To: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-committers@lists.postgresql.org
References: <E1kaQ2c-0005lx-Eg@gemulon.postgresql.org>
Message-ID: <fff35eb5-765c-3e60-3a2a-45ba5f88777d@dunslane.net>
Date: Mon, 9 Nov 2020 16:23:24 -0500
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On 11/4/20 4:10 PM, Tom Lane wrote:
> Declare assorted array functions using anycompatible not anyelement.
>
> Convert array_append, array_prepend, array_cat, array_position,
> array_positions, array_remove, array_replace, and width_bucket
> to use anycompatiblearray.  This is a simple extension of commit
> 5c292e6b9 to hit some other places where there's a pretty obvious
> gain in usability from doing so.
>
> Ideally we'd also modify other functions taking multiple old-style
> polymorphic arguments.  But most of the remainder are tied into one
> or more operator classes, making any such change a much larger can of
> worms than I desire to open right now.
>
> Discussion: https://postgr.es/m/77675130-89da-dab1-51dd-492c93dcf5d1@postgresfriends.org
>


This patch broke cross-version pg_upgrade testing. I have cured crake
for the moment by having it execute this in the source database:

    drop aggregate if exists public.array_cat_accum(anyarray);
    drop aggregate if exists public.first_el_agg_any(anyelement);

But I wonder if we really want to make it impossible to upgrade
databases with aggregates that contain these functions?


cheers


andrew