Drops a cast definition for a UDT from the data dictionary.
You can also drop the system-generated casts for distinct UDTs. The system does not drop the associated external cast routine when you perform DROP CAST.
You should not drop a cast if it is referenced by a view, stored procedure, trigger, or macro. There are no restrictions on dropping a cast. The system always honors a DROP CAST request whether it is referenced by a view, stored procedure, trigger, or macro. However, after you drop a cast, any attempt to use a view, stored procedure, trigger, or macro that references the dropped cast returns an error to the requestor.
This statement is ANSI SQL:2011 compliant.
You must have either the UDTTYPE or the UDTMETHOD privilege on the SYSUDTLIB database to drop a user-defined cast for a UDT.