DROP ROUTINE — remove a routine
DROP ROUTINE [ IF EXISTS ]name[ ( [ [argmode] [argname]argtype[, ...] ] ) ] [, ...] [ CASCADE | RESTRICT ]
DROP ROUTINE removes the definition of one or more
existing routines. The term “routine” includes
aggregate functions, normal functions, and procedures. See
under DROP AGGREGATE, DROP FUNCTION,
and DROP PROCEDURE for the description of the
parameters, more examples, and further details.
The lookup rules used by DROP ROUTINE are
fundamentally the same as for DROP PROCEDURE; in
particular, DROP ROUTINE shares that command's
behavior of considering an argument list that has
no argmode markers to be
possibly using the SQL standard's definition that OUT
arguments are included in the list. (DROP AGGREGATE
and DROP FUNCTION do not do that.)
In some cases where the same name is shared by routines of different
kinds, it is possible for DROP ROUTINE to fail with
an ambiguity error when a more specific command (DROP
FUNCTION, etc.) would work. Specifying the argument type
list more carefully will also resolve such problems.
These lookup rules are also used by other commands that
act on existing routines, such as ALTER ROUTINE
and COMMENT ON ROUTINE.
To drop the routine foo for type
integer:
DROP ROUTINE foo(integer);
This command will work independent of whether foo is an
aggregate, function, or procedure.
This command conforms to the SQL standard, with these PostgreSQL extensions:
The standard only allows one routine to be dropped per command.
The IF EXISTS option is an extension.
The ability to specify argument modes and names is an extension, and the lookup rules differ when modes are given.
User-definable aggregate functions are an extension.
Note that there is no CREATE ROUTINE command.