catalog/catalog.c:GetNewRelFileNode() and its calls indicate that the
following change makes sense:
diff --git a/src/include/storage/relfilenode.h
b/src/include/storage/relfilenode.h
index 75f897f..7190974 100644
--- a/src/include/storage/relfilenode.h
+++ b/src/include/storage/relfilenode.h
@@ -55,7 +55,7 @@ typedef enum ForkNumber * relNode identifies the specific relation. relNode corresponds to *
pg_class.relfilenode(NOT pg_class.oid, because we need to be able * to assign new physical files to relations in some
situations).
- * Notice that relNode is only unique within a particular database.
+ * Notice that relNode is only unique within a particular tablespace. * * Note: spcNode must be GLOBALTABLESPACE_OID
ifand only if dbNode is * zero. We support shared relations only in the "global" tablespace.
// Antonin Houska (Tony)
