PostgreSQL: Documentation: 9.4: System Administration ...
pg_relation_filepath is similar to pg_relation_filenode, but it returns the entire file path name (relative to the database cluster''s data directory PGDATA) of the relation. pg_filenode_relation is the reverse of pg_relation_filenode. Given a "tablespace" OID and a "filenode", it returns the associated relation''s OID. For a table in the ...