*** ./src/backend/access/nbtree/nbtinsert.c.orig	2005-10-08 09:57:33.316123472 +0900
--- ./src/backend/access/nbtree/nbtinsert.c	2005-10-08 11:44:39.725160800 +0900
***************
*** 40,46 ****
  
  static TransactionId _bt_check_unique(Relation rel, BTItem btitem,
  				 Relation heapRel, Buffer buf,
! 				 ScanKey itup_scankey);
  static void _bt_insertonpg(Relation rel, Buffer buf,
  			   BTStack stack,
  			   int keysz, ScanKey scankey,
--- 40,46 ----
  
  static TransactionId _bt_check_unique(Relation rel, BTItem btitem,
  				 Relation heapRel, Buffer buf,
! 				 ScanKey itup_scankey, OffsetNumber *reuse_off);
  static void _bt_insertonpg(Relation rel, Buffer buf,
  			   BTStack stack,
  			   int keysz, ScanKey scankey,
***************
*** 120,128 ****
  	 */
  	if (index_is_unique)
  	{
! 		TransactionId xwait;
  
! 		xwait = _bt_check_unique(rel, btitem, heapRel, buf, itup_scankey);
  
  		if (TransactionIdIsValid(xwait))
  		{
--- 120,130 ----
  	 */
  	if (index_is_unique)
  	{
! 		TransactionId	xwait;
! 		OffsetNumber	reuse_off = InvalidOffsetNumber;
  
! 		xwait = _bt_check_unique(rel, btitem, heapRel, buf, itup_scankey,
! 								 &reuse_off);
  
  		if (TransactionIdIsValid(xwait))
  		{
***************
*** 133,138 ****
--- 135,168 ----
  			_bt_freestack(stack);
  			goto top;
  		}
+ 
+ 		/*
+ 		 * When the reusable item was found, change TID of this item to
+ 		 * new value instead of executing _bt_insertonpg.
+ 		 */
+ 		if (reuse_off != InvalidOffsetNumber)
+ 		{
+ 			Page		page = BufferGetPage(buf);
+ 			ItemId		reuse_itemid = PageGetItemId(page, reuse_off);
+ 			BTItem		reuse_btitem = (BTItem)PageGetItem(page, reuse_itemid);
+ 
+ 			Assert(ItemIdDeleted(reuse_itemid));
+ 			Assert(_bt_isequal(RelationGetDescr(rel), page, reuse_off,
+ 							   natts, itup_scankey));
+ 
+ 			reuse_itemid->lp_flags &= ~LP_DELETE;
+ 			reuse_btitem->bti_itup.t_tid = btitem->bti_itup.t_tid;
+ 
+ 			_bt_wrtbuf(rel, buf);
+ 
+ 			/* be tidy */
+ 			_bt_freestack(stack);
+ 			_bt_freeskey(itup_scankey);
+ 
+ 			/* XXX: WAL stuff is necessary */
+ 
+ 			return;
+ 		}
  	}
  
  	/* do the insertion */
***************
*** 152,158 ****
   */
  static TransactionId
  _bt_check_unique(Relation rel, BTItem btitem, Relation heapRel,
! 				 Buffer buf, ScanKey itup_scankey)
  {
  	TupleDesc	itupdesc = RelationGetDescr(rel);
  	int			natts = rel->rd_rel->relnatts;
--- 182,188 ----
   */
  static TransactionId
  _bt_check_unique(Relation rel, BTItem btitem, Relation heapRel,
! 				 Buffer buf, ScanKey itup_scankey, OffsetNumber *reuse_off)
  {
  	TupleDesc	itupdesc = RelationGetDescr(rel);
  	int			natts = rel->rd_rel->relnatts;
***************
*** 162,167 ****
--- 192,199 ----
  	BTPageOpaque opaque;
  	Buffer		nbuf = InvalidBuffer;
  
+ 	Assert(*reuse_off == InvalidOffsetNumber);
+ 
  	page = BufferGetPage(buf);
  	opaque = (BTPageOpaque) PageGetSpecialPointer(page);
  	maxoff = PageGetMaxOffsetNumber(page);
***************
*** 262,272 ****
--- 294,330 ----
  					{
  						curitemid->lp_flags |= LP_DELETE;
  						SetBufferCommitInfoNeedsSave(buf);
+ 
+ 						if (*reuse_off == InvalidOffsetNumber &&
+ 							page == BufferGetPage(buf))
+ 						{
+ 							/*
+ 							 * The reusable item was found on the current
+ 							 * write locking page. 
+ 							 */
+ 							*reuse_off = offset;
+ 						}
  					}
  					LockBuffer(hbuffer, BUFFER_LOCK_UNLOCK);
  				}
  				ReleaseBuffer(hbuffer);
  			}
+ 			else
+ 			{
+ 				if (*reuse_off == InvalidOffsetNumber &&
+ 					page == BufferGetPage(buf))
+ 				{
+ 					if (!_bt_isequal(itupdesc, page, offset, natts,
+ 									 itup_scankey))
+ 						break;		/* we're past all the equal tuples */
+ 
+ 					/*
+ 					 * The reusable item was found on the current
+ 					 * write locking page. 
+ 					 */
+ 					*reuse_off = offset;
+ 				}
+ 			}
  		}
  
  		/*