A function can be deleted from the database with the DROP FUNCTION statement.
DROP FUNCTION [ IF EXISTS ] name [ (parameters) ] [ CASCADE | RESTRICT ];
name is the name of the function to be deleted.
Note In a PolarDB for PostgreSQL(Compatible with Oracle), you need to specify the parameter list under certain circumstances such as if this is an overloaded function. Oracle requires that the parameter list always be omitted.
Usage of IF EXISTS, CASCADE, or RESTRICT is not compatible with Oracle databases.
The following example describes how to drop the previously created function:
DROP FUNCTION simple_function;