NAME

       ALTER_FOREIGN_DATA_WRAPPER - change the definition of a foreign-data wrapper

SYNOPSIS

       ALTER FOREIGN DATA WRAPPER name
           [ HANDLER handler_function | NO HANDLER ]
           [ VALIDATOR validator_function | NO VALIDATOR ]
           [ OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ]) ]
       ALTER FOREIGN DATA WRAPPER name OWNER TO new_owner
       ALTER FOREIGN DATA WRAPPER name RENAME TO new_name

DESCRIPTION

       ALTER FOREIGN DATA WRAPPER changes the definition of a foreign-data wrapper. The first
       form of the command changes the support functions or the generic options of the
       foreign-data wrapper (at least one clause is required). The second form changes the owner
       of the foreign-data wrapper.

       Only superusers can alter foreign-data wrappers. Additionally, only superusers can own
       foreign-data wrappers.

PARAMETERS

       name
           The name of an existing foreign-data wrapper.

       HANDLER handler_function
           Specifies a new handler function for the foreign-data wrapper.

       NO HANDLER
           This is used to specify that the foreign-data wrapper should no longer have a handler
           function.

           Note that foreign tables that use a foreign-data wrapper with no handler cannot be
           accessed.

       VALIDATOR validator_function
           Specifies a new validator function for the foreign-data wrapper.

           Note that it is possible that pre-existing options of the foreign-data wrapper, or of
           dependent servers, user mappings, or foreign tables, are invalid according to the new
           validator.  PostgreSQL does not check for this. It is up to the user to make sure that
           these options are correct before using the modified foreign-data wrapper. However, any
           options specified in this ALTER FOREIGN DATA WRAPPER command will be checked using the
           new validator.

       NO VALIDATOR
           This is used to specify that the foreign-data wrapper should no longer have a
           validator function.

       OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] )
           Change options for the foreign-data wrapper.  ADD, SET, and DROP specify the action to
           be performed.  ADD is assumed if no operation is explicitly specified. Option names
           must be unique; names and values are also validated using the foreign data wrapper's
           validator function, if any.

       new_owner
           The user name of the new owner of the foreign-data wrapper.

       new_name
           The new name for the foreign-data wrapper.

EXAMPLES

       Change a foreign-data wrapper dbi, add option foo, drop bar:

           ALTER FOREIGN DATA WRAPPER dbi OPTIONS (ADD foo '1', DROP 'bar');

       Change the foreign-data wrapper dbi validator to bob.myvalidator:

           ALTER FOREIGN DATA WRAPPER dbi VALIDATOR bob.myvalidator;

COMPATIBILITY

       ALTER FOREIGN DATA WRAPPER conforms to ISO/IEC 9075-9 (SQL/MED), except that the HANDLER,
       VALIDATOR, OWNER TO, and RENAME clauses are extensions.

SEE ALSO

       CREATE FOREIGN DATA WRAPPER (CREATE_FOREIGN_DATA_WRAPPER(7)), DROP FOREIGN DATA WRAPPER
       (DROP_FOREIGN_DATA_WRAPPER(7))