DROP FUNCTION name ( [ type [, ...] ] ) [ CASCADE | RESTRICT ]
The name (optionally schema-qualified) of an existing function.
The type of a parameter of the function.
Automatically drop objects that depend on the function (such as operators or triggers).
Refuse to drop the function if there are any dependent objects. This is the default.
DROP FUNCTION will remove the definition of an existing function. To execute this command the user must be the owner of the function. The input argument types to the function must be specified, since several different functions may exist with the same name and different argument lists.
Refer to CREATE FUNCTION for information on creating functions.
A DROP FUNCTION statement is defined in SQL99. One of its syntax forms is similar to PostgreSQL's.