PostgreSQL 9.1.2 Documentation
Prev | Up |  | Next

# ALTER FOREIGN DATA WRAPPER

## 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

## 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.

## 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` and `OWNER TO` clauses are extensions.

## See Also

CREATE FOREIGN DATA WRAPPER, DROP FOREIGN DATA WRAPPER

Prev | Home | Next
ALTER EXTENSION | Up | ALTER FOREIGN TABLE