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 49-23. pg_foreign_data_wrapper Columns

Name Type References Description
oid oid Row identifier (hidden attribute; must be explicitly selected)
fdwname name Name of the foreign-data wrapper
fdwowner oid pg_authid .oid Owner of the foreign-data wrapper
fdwhandler oid pg_proc .oid References a handler function that is responsible for supplying execution routines for the foreign-data wrapper. Zero if no handler is provided
fdwvalidator oid pg_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
fdwacl aclitem[] Access privileges; see GRANT and REVOKE for details
fdwoptions text[] Foreign-data wrapper specific options, as "keyword=value" strings