Don't allocate storage for partitioned tables.

Also, don't allow setting reloptions on them, since that would have no
effect given the lack of storage.  The patch does this by introducing
a new reloption kind for which there are currently no reloptions -- we
might have some in the future -- so it adjusts parseRelOptions to
handle that case correctly.

Bumped catversion.  System catalogs that contained reloptions for
partitioned tables are no longer valid; plus, there are now fewer
physical files on disk, which is not technically a catalog change but
still a good reason to re-initdb.

Amit Langote, reviewed by Maksim Milyutin and Kyotaro Horiguchi and
revised a bit by me.

Discussion: http://postgr.es/m/20170331.173326.212311140.horiguchi.kyotaro@lab.ntt.co.jp

doc/src/sgml/ref/create_table.sgml

@@ -1038,6 +1038,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
     If a table parameter value is set and the
     equivalent <literal>toast.</literal> parameter is not, the TOAST table
     will use the table's parameter value.
+    Specifying these parameters for partitioned tables is not supported,
+    but you may specify them for individual leaf partitions.
    </para>
 
    <variablelist>

src/backend/access/common/reloptions.c

@@ -1000,7 +1000,8 @@ extractRelOptions(HeapTuple tuple, TupleDesc tupdesc,
  * array; this is so that the caller can easily locate the default values.
  *
  * If there are no options of the given kind, numrelopts is set to 0 and NULL
- * is returned.
+ * is returned (unless options are illegally supplied despite none being
+ * defined, in which case an error occurs).
  *
  * Note: values of type int, bool and real are allocated as part of the
  * returned array.  Values of type string are allocated separately and must
@@ -1010,7 +1011,7 @@ relopt_value *
 parseRelOptions(Datum options, bool validate, relopt_kind kind,
 				int *numrelopts)
 {
-	relopt_value *reloptions;
+	relopt_value *reloptions = NULL;
 	int			numoptions = 0;
 	int			i;
 	int			j;
@@ -1024,21 +1025,18 @@ parseRelOptions(Datum options, bool validate, relopt_kind kind,
 		if (relOpts[i]->kinds & kind)
 			numoptions++;
 
-	if (numoptions == 0)
+	if (numoptions > 0)
 	{
-		*numrelopts = 0;
-		return NULL;
-	}
+		reloptions = palloc(numoptions * sizeof(relopt_value));
 
-	reloptions = palloc(numoptions * sizeof(relopt_value));
-
-	for (i = 0, j = 0; relOpts[i]; i++)
-	{
-		if (relOpts[i]->kinds & kind)
+		for (i = 0, j = 0; relOpts[i]; i++)
 		{
-			reloptions[j].gen = relOpts[i];
-			reloptions[j].isset = false;
-			j++;
+			if (relOpts[i]->kinds & kind)
+			{
+				reloptions[j].gen = relOpts[i];
+				reloptions[j].isset = false;
+				j++;
+			}
 		}
 	}
 
@@ -1418,8 +1416,10 @@ heap_reloptions(char relkind, Datum reloptions, bool validate)
 			return (bytea *) rdopts;
 		case RELKIND_RELATION:
 		case RELKIND_MATVIEW:
-		case RELKIND_PARTITIONED_TABLE:
 			return default_reloptions(reloptions, validate, RELOPT_KIND_HEAP);
+		case RELKIND_PARTITIONED_TABLE:
+			return default_reloptions(reloptions, validate,
+									  RELOPT_KIND_PARTITIONED);
 		default:
 			/* other relkinds are not supported */
 			return NULL;

src/backend/catalog/heap.c

@@ -293,6 +293,7 @@ heap_create(const char *relname,
 		case RELKIND_VIEW:
 		case RELKIND_COMPOSITE_TYPE:
 		case RELKIND_FOREIGN_TABLE:
+		case RELKIND_PARTITIONED_TABLE:
 			create_storage = false;
 
 			/*
@@ -1347,14 +1348,13 @@ heap_create_with_catalog(const char *relname,
 	if (oncommit != ONCOMMIT_NOOP)
 		register_on_commit_action(relid, oncommit);
 
-	if (relpersistence == RELPERSISTENCE_UNLOGGED)
-	{
-		Assert(relkind == RELKIND_RELATION || relkind == RELKIND_MATVIEW ||
-			   relkind == RELKIND_TOASTVALUE ||
-			   relkind == RELKIND_PARTITIONED_TABLE);
-
+	/*
+	 * Unlogged objects need an init fork, except for partitioned tables which
+	 * have no storage at all.
+	 */
+	if (relpersistence == RELPERSISTENCE_UNLOGGED &&
+		relkind != RELKIND_PARTITIONED_TABLE)
 		heap_create_init_fork(new_rel_desc);
-	}
 
 	/*
 	 * ok, the relation has been cataloged, so close our relations and return
@@ -1378,6 +1378,9 @@ heap_create_with_catalog(const char *relname,
 void
 heap_create_init_fork(Relation rel)
 {
+	Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
+		   rel->rd_rel->relkind == RELKIND_MATVIEW ||
+		   rel->rd_rel->relkind == RELKIND_TOASTVALUE);
 	RelationOpenSmgr(rel);
 	smgrcreate(rel->rd_smgr, INIT_FORKNUM, false);
 	log_smgrcreate(&rel->rd_smgr->smgr_rnode.node, INIT_FORKNUM);
@@ -1824,7 +1827,8 @@ heap_drop_with_catalog(Oid relid)
 	 */
 	if (rel->rd_rel->relkind != RELKIND_VIEW &&
 		rel->rd_rel->relkind != RELKIND_COMPOSITE_TYPE &&
-		rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE)
+		rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
+		rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
 	{
 		RelationDropStorage(rel);
 	}

src/include/access/reloptions.h

@@ -48,8 +48,9 @@ typedef enum relopt_kind
 	RELOPT_KIND_SPGIST = (1 << 8),
 	RELOPT_KIND_VIEW = (1 << 9),
 	RELOPT_KIND_BRIN = (1 << 10),
+	RELOPT_KIND_PARTITIONED = (1 << 11),
 	/* if you add a new kind, make sure you update "last_default" too */
-	RELOPT_KIND_LAST_DEFAULT = RELOPT_KIND_BRIN,
+	RELOPT_KIND_LAST_DEFAULT = RELOPT_KIND_PARTITIONED,
 	/* some compilers treat enums as signed ints, so we can't use 1 << 31 */
 	RELOPT_KIND_MAX = (1 << 30)
 } relopt_kind;

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201703292
+#define CATALOG_VERSION_NO	201703311
 
 #endif