-- policy_is_permissive( schema, table, policy, description )
CREATE OR REPLACE FUNCTION policy_is_permissive( NAME, NAME, NAME, text )
RETURNS TEXT AS $$
DECLARE
    permissive boolean;
BEGIN
    SELECT pp.polpermissive
      FROM pg_catalog.pg_policy AS pp
      JOIN pg_catalog.pg_class AS pc ON pc.oid = pp.polrelid
      JOIN pg_catalog.pg_namespace AS pn ON pn.oid = pc.relnamespace
     WHERE pn.nspname = $1
       AND pc.relname = $2
       AND pp.polname = $3
      INTO permissive;

    RETURN ok( permissive, $4 );
END;
$$ LANGUAGE plpgsql;