The argument identifies the particular function to be dropped and is valid only if there is exactly one function instance with the functionName in the schema. The identified function can have any number of parameters defined for it.

An error will occur in any of the following circumstances:

• If no function with the indicated name exists in the named or implied schema (the error is SQLSTATE 42704)
• If there is more than one specific instance of the function in the named or implied schema
• If you try to drop a user-defined function that is invoked in the generationClause of a generated column
• If you try to drop a user-defined function that is invoked in a view or trigger