47.22. pg_foreign_data_wrapper

This catalog exists in each coordinator and datanode in Postgres-XC as inherited from PostgreSQL. Please note that current release of Postgres-XC does not support foreign data wrapper.

Note: The following description applies both to Postgres-XC and PostgreSQL if not described explicitly.

The catalog pg_foreign_data_wrapper stores foreign-data wrapper definitions. A foreign-data wrapper is the mechanism by which external data, residing on foreign servers, is accessed.

Table 47-22. pg_foreign_data_wrapper Columns

NameTypeReferencesDescription
fdwnamename Name of the foreign-data wrapper
fdwowneroidpg_authid.oidOwner of the foreign-data wrapper
fdwhandleroidpg_proc.oid References a handler function that is responsible for supplying execution routines for the foreign-data wrapper. Zero if no handler is provided
fdwvalidatoroidpg_proc.oid References a validator function that is responsible for checking the validity of the options given to the foreign-data wrapper, as well as options for foreign servers and user mappings using the foreign-data wrapper. Zero if no validator is provided
fdwaclaclitem[]  Access privileges; see GRANT and REVOKE for details
fdwoptionstext[]  Foreign-data wrapper specific options, as "keyword=value" strings