Summary
The catalog pg_foreign_table contains auxiliary information about foreign tables. A foreign table is primarily represented by a pg_class entry, just like a regular table. Its pg_foreign_table entry contains the information that is pertinent only to foreign tables and not any other kind of relation.
(Description quoted from the official PostgreSQL documentation.)
Columns
The pg_foreign_table system catalog exposes the following columns (names, types and descriptions are taken verbatim from the PostgreSQL documentation):
ftrelidoidreferencespg_class.oid
The OID of the pg_class entry for this foreign tableftserveroidreferencespg_foreign_server.oid
OID of the foreign server for this foreign tableftoptionstext[]
Foreign table options, as “keyword=value” strings
Related catalogs
This object references the following other system catalogs:
ftrelid→pg_classftserver→pg_foreign_server
Version applicability
Present in PostgreSQL 17, 18, 19 (verified against each release’s documentation). This is a long-standing system object that also exists in earlier PostgreSQL releases.
Related & references
Reference: PostgreSQL documentation — pg_foreign_table.