Re: [GENERAL] Custom shuffle function stopped working in 9.6 - Mailing list pgsql-general

Alexander Farber <alexander.farber@gmail.com> writes:
> after switching to 9.6.2 from 9.5.3 the following custom function has
> stopped working:

> CREATE OR REPLACE FUNCTION words_shuffle(in_array varchar[])
>         RETURNS varchar[] AS
> $func$
>         SELECT array_agg(letters.x) FROM
>         (SELECT UNNEST(in_array) x ORDER BY RANDOM()) letters;
> $func$ LANGUAGE sql STABLE;

Expansion of SRFs in the targetlist now happens after ORDER BY.
So the ORDER BY is sorting a single dummy row and then the unnest
happens after that.  See

https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=9118d03a8

            regards, tom lane