Provided by: postgresql-client-8.4_8.4.3-1_i386 bug

NAME

       ALTER FUNCTION - change the definition of a function

SYNOPSIS

       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           action [ ... ] [ RESTRICT ]
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           RENAME TO new_name
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           OWNER TO new_owner
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           SET SCHEMA new_schema

       where action is one of:

           CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT
           IMMUTABLE | STABLE | VOLATILE
           [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
           COST execution_cost
           ROWS result_rows
           SET configuration_parameter { TO | = } { value | DEFAULT }
           SET configuration_parameter FROM CURRENT
           RESET configuration_parameter
           RESET ALL

DESCRIPTION

       ALTER FUNCTION changes the definition of a function.

       You  must  own  the  function  to  use  ALTER  FUNCTION.   To  change a
       function’s schema, you must also  have  CREATE  privilege  on  the  new
       schema.   To  alter  the  owner,  you must also be a direct or indirect
       member of the new owning role, and that role must have CREATE privilege
       on the function’s schema. (These restrictions enforce that altering the
       owner doesn’t do anything you couldn’t do by  dropping  and  recreating
       the function.  However, a superuser can alter ownership of any function
       anyway.)

PARAMETERS

       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 ALTER 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  ALTER  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.

       new_name
              The new name of the function.

       new_owner
              The new owner of the function. Note  that  if  the  function  is
              marked SECURITY DEFINER, it will subsequently execute as the new
              owner.

       new_schema
              The new schema for the function.

       CALLED ON NULL INPUT

       RETURNS NULL ON NULL INPUT

       STRICT CALLED ON NULL INPUT changes the function so  that  it  will  be
              invoked when some or all of its arguments are null. RETURNS NULL
              ON NULL INPUT or STRICT changes the function so that it  is  not
              invoked if any of its arguments are null; instead, a null result
              is    assumed     automatically.     See     CREATE     FUNCTION
              [create_function(7)] for more information.

       IMMUTABLE

       STABLE

       VOLATILE
              Change  the volatility of the function to the specified setting.
              See CREATE FUNCTION [create_function(7)] for details.

       [ EXTERNAL ] SECURITY INVOKER

       [ EXTERNAL ] SECURITY DEFINER
              Change whether the function is a security definer  or  not.  The
              key  word  EXTERNAL  is  ignored for SQL conformance. See CREATE
              FUNCTION [create_function(7)] for more  information  about  this
              capability.

       COST execution_cost
              Change the estimated execution cost of the function.  See CREATE
              FUNCTION [create_function(7)] for more information.

       ROWS result_rows
              Change the estimated number of rows returned by a  set-returning
              function.  See  CREATE  FUNCTION  [create_function(7)]  for more
              information.

       configuration_parameter

       value  Add or change the assignment  to  be  made  to  a  configuration
              parameter  when  the function is called. If value is DEFAULT or,
              equivalently, RESET  is  used,  the  function-local  setting  is
              removed, so that the function executes with the value present in
              its environment. Use  RESET  ALL  to  clear  all  function-local
              settings.  SET FROM CURRENT saves the session’s current value of
              the parameter as the value to be applied when  the  function  is
              entered.

              See  SET  [set(7)] and in the documentation for more information
              about allowed parameter names and values.

       RESTRICT
              Ignored for conformance with the SQL standard.

EXAMPLES

       To rename the function sqrt for type integer to square_root:

       ALTER FUNCTION sqrt(integer) RENAME TO square_root;

       To change the owner of the function sqrt for type integer to joe:

       ALTER FUNCTION sqrt(integer) OWNER TO joe;

       To change the schema of the function sqrt for type integer to maths:

       ALTER FUNCTION sqrt(integer) SET SCHEMA maths;

       To adjust the search path that is automatically set for a function:

       ALTER FUNCTION check_password(text) SET search_path = admin, pg_temp;

       To disable automatic setting of search_path for a function:

       ALTER FUNCTION check_password(text) RESET search_path;

       The function will now execute with whatever search path is used by  its
       caller.

COMPATIBILITY

       This   statement  is  partially  compatible  with  the  ALTER  FUNCTION
       statement in the SQL standard. The standard allows more properties of a
       function  to  be modified, but does not provide the ability to rename a
       function, make a function  a  security  definer,  attach  configuration
       parameter  values  to  a  function,  or  change  the  owner, schema, or
       volatility of a function. The standard also requires the  RESTRICT  key
       word, which is optional in PostgreSQL.

SEE ALSO

       CREATE FUNCTION [create_function(7)], DROP FUNCTION [drop_function(7)]