Postgres GROUP BY Array Column

Question

I use postgres & have a table like this :

id   | arr
-------------------
 1   | [A,B,C]
 2   | [C,B,A]
 3   | [A,A,B]
 4   | [B,A,B]

I created a GROUP BY 'arr' query.

SELECT COUNT(*) AS total, "arr" FROM "table" GROUP BY "arr"

... and the result :

total | arr
-------------------
 1    | [A,B,C]
 1    | [C,B,A]
 1    | [A,A,B]
 1    | [B,A,B]

BUT, since [A,B,C] and [C,B,A] have the same elements, so i expected the result should be like this :

total | arr
-------------------
  2   |   [A,B,C]
  2   |   [A,A,B]

Did i miss something (in query) or else? Please help me..

Answer 1

You do not need to create a separate function to do this. It can all be done in a single statement:

select array(select unnest(arr) order by 1) as sorted_arr, count(*)
from t
group by sorted_arr;

Here is a rextester.