Provided by: postgresql-client-9.1_9.1.3-2_i386 bug

NAME

       CREATE_FOREIGN_DATA_WRAPPER - define a new foreign-data wrapper

SYNOPSIS

       CREATE FOREIGN DATA WRAPPER name
           [ HANDLER handler_function | NO HANDLER ]
           [ VALIDATOR validator_function | NO VALIDATOR ]
           [ OPTIONS ( option 'value' [, ... ] ) ]

DESCRIPTION

       CREATE FOREIGN DATA WRAPPER creates a new foreign-data wrapper. The
       user who defines a foreign-data wrapper becomes its owner.

       The foreign-data wrapper name must be unique within the database.

       Only superusers can create foreign-data wrappers.

PARAMETERS

       name
           The name of the foreign-data wrapper to be created.

       HANDLER handler_function
           handler_function is the name of a previously registered function
           that will be called to retrieve the execution functions for foreign
           tables. The handler function must take no arguments, and its return
           type must be fdw_handler.

           It is possible to create a foreign-data wrapper with no handler
           function, but foreign tables using such a wrapper can only be
           declared, not accessed.

       VALIDATOR validator_function
           validator_function is the name of a previously registered function
           that will be called to check the generic options given to the
           foreign-data wrapper, as well as options for foreign servers and
           user mappings using the foreign-data wrapper. If no validator
           function or NO VALIDATOR is specified, then options will not be
           checked at creation time. (Foreign-data wrappers will possibly
           ignore or reject invalid option specifications at run time,
           depending on the implementation.) The validator function must take
           two arguments: one of type text[], which will contain the array of
           options as stored in the system catalogs, and one of type oid,
           which will be the OID of the system catalog containing the options.
           The return type is ignored; the function should report invalid
           options using the ereport(ERROR) function.

       OPTIONS ( option 'value' [, ... ] )
           This clause specifies options for the new foreign-data wrapper. The
           allowed option names and values are specific to each foreign data
           wrapper and are validated using the foreign-data wrapper's
           validator function. Option names must be unique.

NOTES

       At the moment, the foreign-data wrapper functionality is rudimentary.
       There is no support for updating a foreign table, and optimization of
       queries is primitive (and mostly left to the wrapper, too).

       There is one built-in foreign-data wrapper validator function provided:
       postgresql_fdw_validator, which accepts options corresponding to libpq
       connection parameters.

EXAMPLES

       Create a useless foreign-data wrapper dummy:

           CREATE FOREIGN DATA WRAPPER dummy;

       Create a foreign-data wrapper file with handler function
       file_fdw_handler:

           CREATE FOREIGN DATA WRAPPER file HANDLER file_fdw_handler;

       Create a foreign-data wrapper mywrapper with some options:

           CREATE FOREIGN DATA WRAPPER mywrapper
               OPTIONS (debug 'true');

COMPATIBILITY

       CREATE FOREIGN DATA WRAPPER conforms to ISO/IEC 9075-9 (SQL/MED), with
       the exception that the HANDLER and VALIDATOR clauses are extensions and
       the standard clauses LIBRARY and LANGUAGE are not implemented in
       PostgreSQL.

       Note, however, that the SQL/MED functionality as a whole is not yet
       conforming.

SEE ALSO

       ALTER FOREIGN DATA WRAPPER (ALTER_FOREIGN_DATA_WRAPPER(7)), DROP
       FOREIGN DATA WRAPPER (DROP_FOREIGN_DATA_WRAPPER(7)), CREATE SERVER
       (CREATE_SERVER(7)), CREATE USER MAPPING (CREATE_USER_MAPPING(7))