pg_get_userbyid()
pg_get_userbyid(role_oid)
role_oid
SELECT id,name FROM oxla_internal.oxla_role;
id | name ----+--------- 1 | oxla 2 | other_user (2 rows)
SELECT pg_get_userbyid(2);
pg_get_userbyid ----------------- other_user (1 row)