ALTER 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 after changing the validator the options to the foreign-data wrapper, servers, and user mappings have become invalid. It is up to the user to make sure that these options are correct before using the foreign-data wrapper.
- 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.