# 52.23. pg_foreign_data_wrapper
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 52.23. pg_foreign_data_wrapper
Columns
Column Type Description |
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oid oid Row identifier |
fdwname name Name of the foreign-data wrapper |
fdwowner oid (references pg_authid .oid )Owner of the foreign-data wrapper |
fdwhandler oid (references 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 (references 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 Section 5.7 for details |
fdwoptions text[] Foreign-data wrapper specific options, as “keyword=value” strings |