ALTER FOREIGN DATA WRAPPER

ALTER FOREIGN DATA WRAPPER

7

SQL - Language Statements

ALTER FOREIGN DATA WRAPPER

change the definition of a foreign-data wrapper

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

\| CURRENT\_ROLE \| CURRENT\_USER \| SESSION\_USER } 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
========
