Postgres array concatenation aggregate function.

agg.sql

CREATE AGGREGATE array_accum (anyarray)
(
    sfunc = array_cat,
    stype = anyarray,
    initcond = '{}'
);  

Useful and works like a charm. Perhaps consider proposing on the pg-dev list to include it in future version.

This is pretty sweet 👍

Great!

Great Job. Thanks.

Simple and useful ! Thanks !

had to change it for pg 14:

CREATE AGGREGATE array_accum (anycompatiblearray)
(
    sfunc = array_cat,
    stype = anycompatiblearray,
    initcond = '{}'
);  

This is great! Is it possible to adapt this so that you can make the array items distinct?
Example of what I'm thinking:
array_accum(distinct "duplicateList")

had to change it for pg 14:

CREATE AGGREGATE array_accum (anycompatiblearray)
(
    sfunc = array_cat,
    stype = anycompatiblearray,
    initcond = '{}'
);  

Thanks, this version worked for me!