Don't create relfilenode for relations without storage

Some relation kinds had relfilenode set to some non-zero value, but
apparently the actual files did not really exist because creation was
prevented elsewhere.  Get rid of the phony pg_class.relfilenode values.

Catversion bumped, but only because the sanity_test check will fail if
run in a system initdb'd with the previous version.

Reviewed-by: Kyotaro HORIGUCHI, Michael Paquier
Discussion: https://postgr.es/m/20181206215552.fm2ypuxq6nhpwjuc@alvherre.pgsql

src/backend/catalog/heap.c

@@ -324,35 +324,25 @@ heap_create(const char *relname,
 						get_namespace_name(relnamespace), relname),
 				 errdetail("System catalog modifications are currently disallowed.")));
 
-	/*
-	 * Decide if we need storage or not, and handle a couple other special
-	 * cases for particular relkinds.
-	 */
+	/* Handle reltablespace for specific relkinds. */
 	switch (relkind)
 	{
 		case RELKIND_VIEW:
 		case RELKIND_COMPOSITE_TYPE:
 		case RELKIND_FOREIGN_TABLE:
-			create_storage = false;
 
 			/*
 			 * Force reltablespace to zero if the relation has no physical
 			 * storage.  This is mainly just for cleanliness' sake.
+			 *
+			 * Partitioned tables and indexes don't have physical storage
+			 * either, but we want to keep their tablespace settings so that
+			 * their children can inherit it.
 			 */
 			reltablespace = InvalidOid;
 			break;
 
-		case RELKIND_PARTITIONED_TABLE:
-		case RELKIND_PARTITIONED_INDEX:
-			/*
-			 * For partitioned tables and indexes, preserve tablespace so that
-			 * it's used as the tablespace for future partitions.
-			 */
-			create_storage = false;
-			break;
-
 		case RELKIND_SEQUENCE:
-			create_storage = true;
 
 			/*
 			 * Force reltablespace to zero for sequences, since we don't
@@ -361,19 +351,21 @@ heap_create(const char *relname,
 			reltablespace = InvalidOid;
 			break;
 		default:
-			create_storage = true;
 			break;
 	}
 
 	/*
-	 * Unless otherwise requested, the physical ID (relfilenode) is initially
-	 * the same as the logical ID (OID).  When the caller did specify a
-	 * relfilenode, it already exists; do not attempt to create it.
+	 * Decide whether to create storage. If caller passed a valid relfilenode,
+	 * storage is already created, so don't do it here.  Also don't create it
+	 * for relkinds without physical storage.
 	 */
-	if (OidIsValid(relfilenode))
+	if (!RELKIND_HAS_STORAGE(relkind) || OidIsValid(relfilenode))
 		create_storage = false;
 	else
+	{
+		create_storage = true;
 		relfilenode = relid;
+	}
 
 	/*
 	 * Never allow a pg_class entry to explicitly specify the database's

src/backend/utils/cache/relcache.c

@@ -1253,6 +1253,10 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
 static void
 RelationInitPhysicalAddr(Relation relation)
 {
+	/* these relations kinds never have storage */
+	if (!RELKIND_HAS_STORAGE(relation->rd_rel->relkind))
+		return;
+
 	if (relation->rd_rel->reltablespace)
 		relation->rd_node.spcNode = relation->rd_rel->reltablespace;
 	else

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201901031
+#define CATALOG_VERSION_NO	201901041
 
 #endif

src/include/utils/rel.h

@@ -450,13 +450,12 @@ typedef struct ViewOptions
 
 /*
  * RelationIsMapped
- *		True if the relation uses the relfilenode map.
- *
- * NB: this is only meaningful for relkinds that have storage, else it
- * will misleadingly say "true".
+ *		True if the relation uses the relfilenode map.  Note multiple eval
+ *		of argument!
  */
 #define RelationIsMapped(relation) \
-	((relation)->rd_rel->relfilenode == InvalidOid)
+	(RELKIND_HAS_STORAGE((relation)->rd_rel->relkind) && \
+	 ((relation)->rd_rel->relfilenode == InvalidOid))
 
 /*
  * RelationOpenSmgr

src/test/regress/expected/sanity_check.out

@@ -224,3 +224,12 @@ SELECT relname, nspname
 ---------+---------
 (0 rows)
 
+-- check that relations without storage don't have relfilenode
+SELECT relname, relkind
+  FROM pg_class
+ WHERE relkind IN ('v', 'c', 'f', 'p', 'I')
+       AND relfilenode <> 0;
+ relname | relkind 
+---------+---------
+(0 rows)
+

src/test/regress/sql/sanity_check.sql

@@ -31,3 +31,9 @@ SELECT relname, nspname
      AND NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = c.oid
                      AND indkey[0] = a.attnum AND indnatts = 1
                      AND indisunique AND indimmediate);
+
+-- check that relations without storage don't have relfilenode
+SELECT relname, relkind
+  FROM pg_class
+ WHERE relkind IN ('v', 'c', 'f', 'p', 'I')
+       AND relfilenode <> 0;