centos man page for drop_function

DROP 
FUNCTION(7)					  PostgreSQL 9.2.7 Documentation					  DROP FUNCTION(7)

NAME
       DROP_FUNCTION - remove a function

SYNOPSIS
       DROP FUNCTION [ IF EXISTS ] name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
	   [ CASCADE | RESTRICT ]

DESCRIPTION
       DROP FUNCTION removes the definition of an existing function. To execute this command the user must be the owner of the function. The
       argument types to the function must be specified, since several different functions can exist with the same name and different argument
       lists.

PARAMETERS
       IF EXISTS
	   Do not throw an error if the function does not exist. A notice is issued in this case.

       name
	   The name (optionally schema-qualified) of an existing function.

       argmode
	   The mode of an argument: IN, OUT, INOUT, or VARIADIC. If omitted, the default is IN. Note that DROP FUNCTION does not actually pay any
	   attention to OUT arguments, since only the input arguments are needed to determine the function's identity. So it is sufficient to list
	   the IN, INOUT, and VARIADIC arguments.

       argname
	   The name of an argument. Note that DROP FUNCTION does not actually pay any attention to argument names, since only the argument data
	   types are needed to determine the function's identity.

       argtype
	   The data type(s) of the function's arguments (optionally schema-qualified), if any.

       CASCADE
	   Automatically drop objects that depend on the function (such as operators or triggers).

       RESTRICT
	   Refuse to drop the function if any objects depend on it. This is the default.

EXAMPLES
       This command removes the square root function:

	   DROP FUNCTION sqrt(integer);

COMPATIBILITY
       A DROP FUNCTION statement is defined in the SQL standard, but it is not compatible with this command.

SEE ALSO
       CREATE FUNCTION (CREATE_FUNCTION(7)), ALTER FUNCTION (ALTER_FUNCTION(7))

PostgreSQL 9.2.7						    2014-02-17							  DROP FUNCTION(7)