PG_FOREIGN_DATA_WRAPPER

PG_FOREIGN_DATA_WRAPPER stores foreign-data wrapper definitions. A foreign-data wrapper is the mechanism by which foreign data resides on foreign servers and is accessible.

**Table 1** PG_FOREIGN_DATA_WRAPPER columns
Column	Type	Reference	Description
oid	oid	-	Row identifier (a hidden attribute that is only shown upon explicit selection).
fdwname	name	-	Name of a foreign-data wrapper.
fdwowner	oid	PG_AUTHID.oid	Owner of the foreign-data wrapper.
fdwhandler	oid	PG_PROC.oid	References a handler function that provides extended routines for the foreign-data wrapper. The value is 0 if no handler function is provided.
fdwvalidator	oid	PG_PROC.oid	References a validator function responsible for validating the options given to the foreign-data wrapper, the foreign-server options, and the user mappings using the foreign-data wrapper. The value is 0 if no validator function is provided.
fdwacl	aclitem[]	-	Access permissions.
fdwoptions	text[]	-	Foreign-data wrapper-specific options, using strings in the keyword=value format.