diff -ruN ../base/src/backend/access/common/heaptuple.c src/backend/access/common/heaptuple.c
--- ../base/src/backend/access/common/heaptuple.c	2002-07-16 19:35:34.000000000 +0200
+++ src/backend/access/common/heaptuple.c	2002-07-16 19:58:01.000000000 +0200
@@ -597,6 +597,9 @@
 	if (hasnull)
 		len += BITMAPLEN(numberOfAttributes);
 
+	if (tupleDescriptor->tdhasoid == WITHOID)
+		len += sizeof(Oid);
+
 	hoff = len = MAXALIGN(len); /* align user data safely */
 
 	len += ComputeDataSize(tupleDescriptor, value, nulls);
@@ -757,8 +760,8 @@
 
 	/* header needs no null bitmap */
 	hoff = offsetof(HeapTupleHeaderData, t_bits);
-	/*if (withoid)
-		hoff += sizeof(Oid);*/
+	if (withoid)
+		hoff += sizeof(Oid);
 	hoff = MAXALIGN(hoff);
 	len = hoff + structlen;
 
diff -ruN ../base/src/backend/access/heap/tuptoaster.c src/backend/access/heap/tuptoaster.c
--- ../base/src/backend/access/heap/tuptoaster.c	2002-05-27 23:52:41.000000000 +0200
+++ src/backend/access/heap/tuptoaster.c	2002-07-16 19:58:01.000000000 +0200
@@ -726,6 +726,8 @@
 		new_len = offsetof(HeapTupleHeaderData, t_bits);
 		if (has_nulls)
 			new_len += BITMAPLEN(numAttrs);
+		if (rel->rd_rel->relhasoids)
+			new_len += sizeof(Oid);
 		new_len = MAXALIGN(new_len);
 		Assert(new_len == olddata->t_hoff);
 		new_len += ComputeDataSize(tupleDesc, toast_values, toast_nulls);
diff -ruN ../base/src/include/access/htup.h src/include/access/htup.h
--- ../base/src/include/access/htup.h	2002-07-15 16:52:05.000000000 +0200
+++ src/include/access/htup.h	2002-07-16 19:58:01.000000000 +0200
@@ -70,8 +70,6 @@
 */
 typedef struct HeapTupleHeaderData
 {
-	Oid			t_oid;			/* OID of this tuple -- 4 bytes */
-
 	TransactionId t_xmin;		/* Xmin -- 4 bytes each */
 	TransactionId t_cid;		/* Cmin, Cmax, Xvac */
 	TransactionId t_xmax;		/* Xmax, Cmax */
@@ -84,7 +82,7 @@
 
 	uint8		t_hoff;			/* sizeof header incl. bitmap, padding */
 
-	/* ^ - 27 bytes - ^ */
+	/* ^ - 23 bytes - ^ */
 
 	bits8		t_bits[1];		/* bitmap of NULLs -- VARIABLE LENGTH */
 
@@ -127,18 +125,19 @@
 
 #ifdef DEBUG_TUPLE_ACCESS
 
-#define HeapTupleHeaderExpectedLen(tup) \
+#define HeapTupleHeaderExpectedLen(tup, withoid) \
 	MAXALIGN(offsetof(HeapTupleHeaderData, t_bits) + \
 	         (((tup)->t_infomask & HEAP_HASNULL) \
-	          ? BITMAPLEN((tup)->t_natts) : 0) \
+	          ? BITMAPLEN((tup)->t_natts) : 0) + \
+		     ((withoid) ? sizeof(Oid) : 0) \
 	        ) 
 
-#define AssertHeapTupleHeaderHoffIsValid(tup) \
-	AssertMacro((tup)->t_hoff == HeapTupleHeaderExpectedLen(tup))
+#define AssertHeapTupleHeaderHoffIsValid(tup, withoid) \
+	AssertMacro((tup)->t_hoff == HeapTupleHeaderExpectedLen(tup, withoid))
 
 #else
 
-#define AssertHeapTupleHeaderHoffIsValid(tup) ((void)true)
+#define AssertHeapTupleHeaderHoffIsValid(tup, withoid) ((void)true)
 
 #endif  /* DEBUG_TUPLE_ACCESS */
 
@@ -147,14 +146,14 @@
 
 #define HeapTupleHeaderGetOid(tup) \
 ( \
-	AssertHeapTupleHeaderHoffIsValid(tup), \
-	(tup)->t_oid \
+	AssertHeapTupleHeaderHoffIsValid(tup, true), \
+	*((Oid *)((char *)(tup) + (tup)->t_hoff - sizeof(Oid))) \
 )
 
 #define HeapTupleHeaderSetOid(tup, oid) \
 ( \
-	AssertHeapTupleHeaderHoffIsValid(tup), \
-	(tup)->t_oid = (oid) \
+	AssertHeapTupleHeaderHoffIsValid(tup, true), \
+	*((Oid *)((char *)(tup) + (tup)->t_hoff - sizeof(Oid))) = (oid) \
 )