diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c
index f034bf13a9..6200f953eb 100644
--- a/src/backend/access/common/heaptuple.c
+++ b/src/backend/access/common/heaptuple.c
@@ -16,7 +16,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/common/heaptuple.c,v 1.113 2007/01/05 22:19:21 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/common/heaptuple.c,v 1.114 2007/01/09 22:00:59 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -295,7 +295,7 @@ DataFill(char *data,
 bool
 heap_attisnull(HeapTuple tup, int attnum)
 {
-	if (attnum > (int) tup->t_data->t_natts)
+	if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
 		return true;
 
 	if (attnum > 0)
@@ -474,6 +474,7 @@ nocachegetattr(HeapTuple tuple,
 	{
 		int			j = 1;
 		long		off;
+		int			natts = HeapTupleHeaderGetNatts(tup);
 
 		/*
 		 * need to set cache for some atts
@@ -488,7 +489,7 @@ nocachegetattr(HeapTuple tuple,
 
 		for (; j <= attnum ||
 		/* Can we compute more?  We will probably need them */
-			 (j < tup->t_natts &&
+			 (j < natts &&
 			  att[j]->attcacheoff == -1 &&
 			  (HeapTupleNoNulls(tuple) || !att_isnull(j, bp)) &&
 			  (HeapTupleAllFixed(tuple) || att[j]->attlen > 0)); j++)
@@ -739,7 +740,7 @@ heap_form_tuple(TupleDesc tupleDescriptor,
 	HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid);
 	HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod);
 
-	td->t_natts = numberOfAttributes;
+	HeapTupleHeaderSetNatts(td, numberOfAttributes);
 	td->t_hoff = hoff;
 
 	if (tupleDescriptor->tdhasoid)		/* else leave infomask = 0 */
@@ -846,7 +847,7 @@ heap_formtuple(TupleDesc tupleDescriptor,
 	HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid);
 	HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod);
 
-	td->t_natts = numberOfAttributes;
+	HeapTupleHeaderSetNatts(td, numberOfAttributes);
 	td->t_hoff = hoff;
 
 	if (tupleDescriptor->tdhasoid)		/* else leave infomask = 0 */
@@ -1035,7 +1036,7 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 	bits8	   *bp = tup->t_bits;		/* ptr to null bitmap in tuple */
 	bool		slow = false;	/* can we use/set attcacheoff? */
 
-	natts = tup->t_natts;
+	natts = HeapTupleHeaderGetNatts(tup);
 
 	/*
 	 * In inheritance situations, it is possible that the given tuple actually
@@ -1128,7 +1129,7 @@ heap_deformtuple(HeapTuple tuple,
 	bits8	   *bp = tup->t_bits;		/* ptr to null bitmap in tuple */
 	bool		slow = false;	/* can we use/set attcacheoff? */
 
-	natts = tup->t_natts;
+	natts = HeapTupleHeaderGetNatts(tup);
 
 	/*
 	 * In inheritance situations, it is possible that the given tuple actually
@@ -1335,7 +1336,7 @@ slot_getattr(TupleTableSlot *slot, int attnum, bool *isnull)
 	 * than the tupdesc.)
 	 */
 	tup = tuple->t_data;
-	if (attnum > tup->t_natts)
+	if (attnum > HeapTupleHeaderGetNatts(tup))
 	{
 		*isnull = true;
 		return (Datum) 0;
@@ -1401,7 +1402,7 @@ slot_getallattrs(TupleTableSlot *slot)
 	/*
 	 * load up any slots available from physical tuple
 	 */
-	attnum = tuple->t_data->t_natts;
+	attnum = HeapTupleHeaderGetNatts(tuple->t_data);
 	attnum = Min(attnum, tdesc_natts);
 
 	slot_deform_tuple(slot, attnum);
@@ -1448,7 +1449,7 @@ slot_getsomeattrs(TupleTableSlot *slot, int attnum)
 	/*
 	 * load up any slots available from physical tuple
 	 */
-	attno = tuple->t_data->t_natts;
+	attno = HeapTupleHeaderGetNatts(tuple->t_data);
 	attno = Min(attno, attnum);
 
 	slot_deform_tuple(slot, attno);
@@ -1601,7 +1602,7 @@ heap_form_minimal_tuple(TupleDesc tupleDescriptor,
 	 * And fill in the information.
 	 */
 	tuple->t_len = len;
-	tuple->t_natts = numberOfAttributes;
+	HeapTupleHeaderSetNatts(tuple, numberOfAttributes);
 	tuple->t_hoff = hoff + MINIMAL_TUPLE_OFFSET;
 
 	if (tupleDescriptor->tdhasoid)		/* else leave infomask = 0 */
@@ -1663,7 +1664,7 @@ heap_tuple_from_minimal_tuple(MinimalTuple mtup)
 	result->t_tableOid = InvalidOid;
 	result->t_data = (HeapTupleHeader) ((char *) result + HEAPTUPLESIZE);
 	memcpy((char *) result->t_data + MINIMAL_TUPLE_OFFSET, mtup, mtup->t_len);
-	memset(result->t_data, 0, offsetof(HeapTupleHeaderData, t_natts));
+	memset(result->t_data, 0, offsetof(HeapTupleHeaderData, t_infomask2));
 	return result;
 }
 
@@ -1729,7 +1730,7 @@ heap_addheader(int natts,		/* max domain index */
 
 	/* we don't bother to fill the Datum fields */
 
-	td->t_natts = natts;
+	HeapTupleHeaderSetNatts(td, natts);
 	td->t_hoff = hoff;
 
 	if (withoid)				/* else leave infomask = 0 */
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 3f489d4225..3913391f6f 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.223 2007/01/05 22:19:22 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.224 2007/01/09 22:00:59 momjian Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -1455,7 +1455,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid,
 		rdata[0].buffer = InvalidBuffer;
 		rdata[0].next = &(rdata[1]);
 
-		xlhdr.t_natts = heaptup->t_data->t_natts;
+		xlhdr.t_infomask2 = heaptup->t_data->t_infomask2;
 		xlhdr.t_infomask = heaptup->t_data->t_infomask;
 		xlhdr.t_hoff = heaptup->t_data->t_hoff;
 
@@ -3204,7 +3204,7 @@ log_heap_update(Relation reln, Buffer oldbuf, ItemPointerData from,
 	rdata[1].buffer_std = true;
 	rdata[1].next = &(rdata[2]);
 
-	xlhdr.hdr.t_natts = newtup->t_data->t_natts;
+	xlhdr.hdr.t_infomask2 = newtup->t_data->t_infomask2;
 	xlhdr.hdr.t_infomask = newtup->t_data->t_infomask;
 	xlhdr.hdr.t_hoff = newtup->t_data->t_hoff;
 	if (move)					/* remember xmax & xmin */
@@ -3503,7 +3503,7 @@ heap_xlog_insert(XLogRecPtr lsn, XLogRecord *record)
 		   (char *) xlrec + SizeOfHeapInsert + SizeOfHeapHeader,
 		   newlen);
 	newlen += offsetof(HeapTupleHeaderData, t_bits);
-	htup->t_natts = xlhdr.t_natts;
+	htup->t_infomask2 = xlhdr.t_infomask2;
 	htup->t_infomask = xlhdr.t_infomask;
 	htup->t_hoff = xlhdr.t_hoff;
 	HeapTupleHeaderSetXmin(htup, record->xl_xid);
@@ -3666,7 +3666,7 @@ newsame:;
 		   (char *) xlrec + hsize,
 		   newlen);
 	newlen += offsetof(HeapTupleHeaderData, t_bits);
-	htup->t_natts = xlhdr.t_natts;
+	htup->t_infomask2 = xlhdr.t_infomask2;
 	htup->t_infomask = xlhdr.t_infomask;
 	htup->t_hoff = xlhdr.t_hoff;
 
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 49a3446d93..a565ba3cd2 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.168 2007/01/05 22:19:29 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.169 2007/01/09 22:00:59 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -651,7 +651,7 @@ SPI_getvalue(HeapTuple tuple, TupleDesc tupdesc, int fnumber)
 
 	SPI_result = 0;
 
-	if (fnumber > tuple->t_data->t_natts || fnumber == 0 ||
+	if (fnumber > HeapTupleHeaderGetNatts(tuple->t_data) || fnumber == 0 ||
 		fnumber <= FirstLowInvalidHeapAttributeNumber)
 	{
 		SPI_result = SPI_ERROR_NOATTRIBUTE;
@@ -692,7 +692,7 @@ SPI_getbinval(HeapTuple tuple, TupleDesc tupdesc, int fnumber, bool *isnull)
 {
 	SPI_result = 0;
 
-	if (fnumber > tuple->t_data->t_natts || fnumber == 0 ||
+	if (fnumber > HeapTupleHeaderGetNatts(tuple->t_data) || fnumber == 0 ||
 		fnumber <= FirstLowInvalidHeapAttributeNumber)
 	{
 		SPI_result = SPI_ERROR_NOATTRIBUTE;
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 49a874244d..eb78010906 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.118 2007/01/05 22:19:51 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.119 2007/01/09 22:01:00 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -98,7 +98,7 @@ extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
 	( \
 		((attnum) > 0) ? \
 		( \
-			((attnum) > (int) (tup)->t_data->t_natts) ? \
+			((attnum) > (int) HeapTupleHeaderGetNatts((tup)->t_data)) ? \
 			( \
 				(((isnull) != NULL) ? (*(isnull) = true) : (dummyret)NULL), \
 				(Datum)NULL \
diff --git a/src/include/access/htup.h b/src/include/access/htup.h
index 7c1205cdbf..ddde6a466d 100644
--- a/src/include/access/htup.h
+++ b/src/include/access/htup.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/htup.h,v 1.88 2007/01/05 22:19:51 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/htup.h,v 1.89 2007/01/09 22:01:00 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -139,7 +139,7 @@ typedef struct HeapTupleHeaderData
 
 	/* Fields below here must match MinimalTupleData! */
 
-	int16		t_natts;		/* number of attributes */
+	uint16		t_infomask2;	/* number of attributes + various flags */
 
 	uint16		t_infomask;		/* various flag bits, see below */
 
@@ -182,6 +182,15 @@ typedef HeapTupleHeaderData *HeapTupleHeader;
 
 #define HEAP_XACT_MASK			0xFFC0	/* visibility-related bits */
 
+/* information stored in t_infomask2, and accessor macros */
+#define HEAP_NATTS_MASK			0x7FF	/* 11 bits for number of attributes */
+/* bits 0xF800 are unused */
+
+#define HeapTupleHeaderGetNatts(tup) ((tup)->t_infomask2 & HEAP_NATTS_MASK)
+#define HeapTupleHeaderSetNatts(tup, natts) \
+( \
+	(tup)->t_infomask2 = ((tup)->t_infomask2 & ~HEAP_NATTS_MASK) | (natts) \
+)
 
 /*
  * HeapTupleHeader accessor macros
@@ -367,8 +376,8 @@ do { \
  * and thereby prevent accidental use of the nonexistent fields.
  *
  * MinimalTupleData contains a length word, some padding, and fields matching
- * HeapTupleHeaderData beginning with t_natts.	The padding is chosen so that
- * offsetof(t_natts) is the same modulo MAXIMUM_ALIGNOF in both structs.
+ * HeapTupleHeaderData beginning with t_infomask2. The padding is chosen so that
+ * offsetof(t_infomask2) is the same modulo MAXIMUM_ALIGNOF in both structs.
  * This makes data alignment rules equivalent in both cases.
  *
  * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is
@@ -380,9 +389,9 @@ do { \
  * the MINIMAL_TUPLE_OFFSET distance.  t_len does not include that, however.
  */
 #define MINIMAL_TUPLE_OFFSET \
-	((offsetof(HeapTupleHeaderData, t_natts) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF)
+	((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF)
 #define MINIMAL_TUPLE_PADDING \
-	((offsetof(HeapTupleHeaderData, t_natts) - sizeof(uint32)) % MAXIMUM_ALIGNOF)
+	((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF)
 
 typedef struct MinimalTupleData
 {
@@ -392,7 +401,7 @@ typedef struct MinimalTupleData
 
 	/* Fields below here must match HeapTupleHeaderData! */
 
-	int16		t_natts;		/* number of attributes */
+	uint16		t_infomask2;	/* number of attributes + various flags */
 
 	uint16		t_infomask;		/* various flag bits, see below */
 
@@ -552,7 +561,7 @@ typedef struct xl_heap_delete
  */
 typedef struct xl_heap_header
 {
-	int16		t_natts;
+	uint16		t_infomask2;
 	uint16		t_infomask;
 	uint8		t_hoff;
 } xl_heap_header;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 95598cee5a..e4d563b4d2 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.182 2007/01/05 22:20:02 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.183 2007/01/09 22:01:00 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -4092,7 +4092,7 @@ exec_move_row(PLpgSQL_execstate *estate,
 	 * Row is a bit more complicated in that we assign the individual
 	 * attributes of the tuple to the variables the row points to.
 	 *
-	 * NOTE: this code used to demand row->nfields == tup->t_data->t_natts,
+	 * NOTE: this code used to demand row->nfields == HeapTupleHeaderGetNatts(tup->t_data,
 	 * but that's wrong.  The tuple might have more fields than we expected if
 	 * it's from an inheritance-child table of the current table, or it might
 	 * have fewer if the table has had columns added by ALTER TABLE. Ignore
@@ -4110,7 +4110,7 @@ exec_move_row(PLpgSQL_execstate *estate,
 		int			anum;
 
 		if (HeapTupleIsValid(tup))
-			t_natts = tup->t_data->t_natts;
+			t_natts = HeapTupleHeaderGetNatts(tup->t_data);
 		else
 			t_natts = 0;