Re: Custom shuffle function stopped working in 9.6

On 02/11/2017 09:17 AM, Alexander Farber wrote:
> I think ORDER BY RANDOM() has stopped working in 9.6.2:
>
> words=> select unnest(ARRAY['a','b','c','d','e','f']) order by random();
> unnest
> --------
> a
> b
> c
> d
> e
> f
> (6 rows)
>

So back to your original question:

CREATE OR REPLACE FUNCTION public.words_shuffle(in_array character
varying[])
RETURNS character varying[]
LANGUAGE sql
STABLE
AS $function$
SELECT array_agg(letters.x) FROM
(SELECT * FROM UNNEST(in_array) x ORDER BY RANDOM()) letters;
$function$

postgres=> select * from words_shuffle(ARRAY['a','b','c','d','e','f']);
words_shuffle
---------------
{d,f,a,e,c,b}
(1 row)

postgres=> select * from words_shuffle(ARRAY['a','b','c','d','e','f']);
words_shuffle
---------------
{c,d,a,e,f,b}
(1 row)

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com