Provided by: postgresql-client-8.4_8.4.11-1_amd64 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)]