1. Could you add pass-through support for more PostgreSQL functions as in:

      postgresMethods.put("array_to_string",new PassthroughMethod("array_to_string",JdbcType.VARCHAR,2,2));
      postgresMethods.put("string_agg",new PassthroughMethod("string_agg",JdbcType.VARCHAR,2,2));

2. And one that's somewhat harder because it's using the JdbcType.ARRAY which you haven't used before:

        postgresMethods.put("array_agg",new PassthroughMethod("array_agg",JdbcType.ARRAY,1,1));

3. And possibly support for using the DISTINCT keyword inside of function calls like:

   SELECT array_agg(DISTINCT a.visit) FROM a GROUP BY visit;

Thanks.