Add PARALLEL parameter to functions

scripts-available/CDB_Conf.sql

@@ -26,7 +26,7 @@ BEGIN
     PERFORM cartodb.CDB_Conf_RemoveConf(key);
     EXECUTE 'INSERT INTO cartodb.CDB_CONF (KEY, VALUE) VALUES ($1, $2);' USING key, value;
 END
-$$ LANGUAGE PLPGSQL VOLATILE;
+$$ LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
 
 CREATE OR REPLACE
 FUNCTION cartodb.CDB_Conf_RemoveConf(key text)
@@ -34,7 +34,7 @@ FUNCTION cartodb.CDB_Conf_RemoveConf(key text)
 BEGIN
     EXECUTE 'DELETE FROM cartodb.CDB_CONF WHERE KEY = $1;' USING key;
 END
-$$ LANGUAGE PLPGSQL VOLATILE;
+$$ LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
 
 CREATE OR REPLACE
 FUNCTION cartodb.CDB_Conf_GetConf(key text)
@@ -45,4 +45,4 @@ BEGIN
     EXECUTE 'SELECT VALUE FROM cartodb.CDB_CONF WHERE KEY = $1;' INTO value USING key;
     RETURN value;
 END
-$$ LANGUAGE PLPGSQL STABLE;
+$$ LANGUAGE PLPGSQL STABLE PARALLEL SAFE;