Concat for array in Spark SQL is not the one in PostgreSQL but array_cat

postgres=# select array_cat(array[1,2], array[2]);
 array_cat
-----------
 {1,2,2}
(1 row)

postgres=# select concat(array[1,2], array[2]);
  concat
----------
 {1,2}{2}
(1 row)

// Some comments here
spark-sql> select concat(array(1,2), array(2));
[1,2,2]