Alter and drop UDFs

After you register a UDF, you can use the ALTER FUNCTION command to change the function object files, return value, memory usage options, or logging level. You cannot change the function name or argument type list; you must drop the existing function and then create a function with the new name, argument type list, or both.

You can remove a UDF by using the DROP FUNCTION command. The system does not allow you to drop UDFs that are referenced in any tables or views. You must resolve those dependencies before you can drop the UDX, as described in Dependency checks before you drop UDXs.

The dependency checks do not stop a DROP FUNCTION operation if the UDF was used in a table or view that was created on an earlier Netezza Performance Server release environment and which was later upgraded to release 4.6. You would need to re-create the old view or modify the default expression after the 4.6 upgrade to take advantage of the dependency checks.