Redefine the lp_flags field of item pointers as having four states, rather

than two independent bits (one of which was never used in heap pages anyway,
or at least hadn't been in a very long time).  This gives us flexibility to
add the HOT notions of redirected and dead item pointers without requiring
anything so klugy as magic values of lp_off and lp_len.  The state values
are chosen so that for the states currently in use (pre-HOT) there is no
change in the physical representation.

31 files changed, 248 insertions, 155 deletions

diff --git a/contrib/pageinspect/btreefuncs.c b/contrib/pageinspect/btreefuncs.c
index e8063d42c6..6251fd5b5f 100644
--- a/contrib/pageinspect/btreefuncs.c
+++ b/contrib/pageinspect/btreefuncs.c
@@ -140,7 +140,7 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
 
 		item_size += IndexTupleSize(itup);
 
-		if (!ItemIdDeleted(id))
+		if (!ItemIdIsDead(id))
 			stat->live_items++;
 		else
 			stat->dead_items++;
diff --git a/contrib/pageinspect/heapfuncs.c b/contrib/pageinspect/heapfuncs.c
index 600a5242ff..bf5b53bb6b 100644
--- a/contrib/pageinspect/heapfuncs.c
+++ b/contrib/pageinspect/heapfuncs.c
@@ -156,15 +156,15 @@ heap_page_items(PG_FUNCTION_ARGS)
 		 * could be corrupt in many other ways, but at least we won't 
 		 * crash.
 		 */
-		if ((lp_len >= sizeof(HeapTupleHeader)) &&
-			(lp_offset == MAXALIGN(lp_offset)) &&
-			(lp_offset + lp_len <= raw_page_size) &&
-			ItemIdIsUsed(id))
+		if (ItemIdHasStorage(id) &&
+			lp_len >= sizeof(HeapTupleHeader) &&
+			lp_offset == MAXALIGN(lp_offset) &&
+			lp_offset + lp_len <= raw_page_size)
 		{
 			HeapTupleHeader	tuphdr;
 			int				bits_len;
 
-			/* Extract infromation from the tuple header */
+			/* Extract information from the tuple header */
 
 			tuphdr = (HeapTupleHeader) PageGetItem(page, id);
 		
diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
index 9bb88c0a85..126d0bcdac 100644
--- a/contrib/pgstattuple/pgstattuple.c
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -477,7 +477,7 @@ pgstat_index_page(pgstattuple_type * stat, Page page,
 	{
 		ItemId		itemid = PageGetItemId(page, i);
 
-		if (ItemIdDeleted(itemid))
+		if (ItemIdIsDead(itemid))
 		{
 			stat->dead_tuple_count++;
 			stat->dead_tuple_len += ItemIdGetLength(itemid);
diff --git a/src/backend/access/gin/ginentrypage.c b/src/backend/access/gin/ginentrypage.c
index d22d26b4ca..eff0ae610a 100644
--- a/src/backend/access/gin/ginentrypage.c
+++ b/src/backend/access/gin/ginentrypage.c
@@ -359,7 +359,7 @@ entryPlaceToPage(GinBtree btree, Buffer buf, OffsetNumber off, XLogRecData **prd
 	*prdata = rdata;
 	data.updateBlkno = entryPreparePage(btree, page, off);
 
-	placed = PageAddItem(page, (Item) btree->entry, IndexTupleSize(btree->entry), off, LP_USED);
+	placed = PageAddItem(page, (Item) btree->entry, IndexTupleSize(btree->entry), off, false);
 	if (placed != off)
 		elog(ERROR, "failed to add item to index page in \"%s\"",
 			 RelationGetRelationName(btree->index));
@@ -488,7 +488,7 @@ entrySplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogR
 			lsize += MAXALIGN(IndexTupleSize(itup)) + sizeof(ItemIdData);
 		}
 
-		if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, LP_USED) == InvalidOffsetNumber)
+		if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false) == InvalidOffsetNumber)
 			elog(ERROR, "failed to add item to index page in \"%s\"",
 				 RelationGetRelationName(btree->index));
 		ptr += MAXALIGN(IndexTupleSize(itup));
@@ -563,11 +563,11 @@ entryFillRoot(GinBtree btree, Buffer root, Buffer lbuf, Buffer rbuf)
 	page = BufferGetPage(root);
 
 	itup = ginPageGetLinkItup(lbuf);
-	if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, LP_USED) == InvalidOffsetNumber)
+	if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false) == InvalidOffsetNumber)
 		elog(ERROR, "failed to add item to index root page");
 
 	itup = ginPageGetLinkItup(rbuf);
-	if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, LP_USED) == InvalidOffsetNumber)
+	if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false) == InvalidOffsetNumber)
 		elog(ERROR, "failed to add item to index root page");
 }
 
diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index 02313e659f..0ae4f17a23 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -544,7 +544,7 @@ ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint3
 				itup = GinFormTuple(&gvs->ginstate, value, GinGetPosting(itup), newN);
 				PageIndexTupleDelete(tmppage, i);
 
-				if (PageAddItem(tmppage, (Item) itup, IndexTupleSize(itup), i, LP_USED) != i)
+				if (PageAddItem(tmppage, (Item) itup, IndexTupleSize(itup), i, false) != i)
 					elog(ERROR, "failed to add item to index page in \"%s\"",
 						 RelationGetRelationName(gvs->index));
 
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c
index 811f6d9609..74d30e4edf 100644
--- a/src/backend/access/gin/ginxlog.c
+++ b/src/backend/access/gin/ginxlog.c
@@ -199,7 +199,7 @@ ginRedoInsert(XLogRecPtr lsn, XLogRecord *record)
 
 		itup = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogInsert));
 
-		if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), data->offset, LP_USED) == InvalidOffsetNumber)
+		if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), data->offset, false) == InvalidOffsetNumber)
 			elog(ERROR, "failed to add item to index page in %u/%u/%u",
 				 data->node.spcNode, data->node.dbNode, data->node.relNode);
 
@@ -281,7 +281,7 @@ ginRedoSplit(XLogRecPtr lsn, XLogRecord *record)
 
 		for (i = 0; i < data->separator; i++)
 		{
-			if (PageAddItem(lpage, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, LP_USED) == InvalidOffsetNumber)
+			if (PageAddItem(lpage, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false) == InvalidOffsetNumber)
 				elog(ERROR, "failed to add item to index page in %u/%u/%u",
 				  data->node.spcNode, data->node.dbNode, data->node.relNode);
 			itup = (IndexTuple) (((char *) itup) + MAXALIGN(IndexTupleSize(itup)));
@@ -289,7 +289,7 @@ ginRedoSplit(XLogRecPtr lsn, XLogRecord *record)
 
 		for (i = data->separator; i < data->nitem; i++)
 		{
-			if (PageAddItem(rpage, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, LP_USED) == InvalidOffsetNumber)
+			if (PageAddItem(rpage, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false) == InvalidOffsetNumber)
 				elog(ERROR, "failed to add item to index page in %u/%u/%u",
 				  data->node.spcNode, data->node.dbNode, data->node.relNode);
 			itup = (IndexTuple) (((char *) itup) + MAXALIGN(IndexTupleSize(itup)));
@@ -375,7 +375,7 @@ ginRedoVacuumPage(XLogRecPtr lsn, XLogRecord *record)
 
 		for (i = 0; i < data->nitem; i++)
 		{
-			if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, LP_USED) == InvalidOffsetNumber)
+			if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false) == InvalidOffsetNumber)
 				elog(ERROR, "failed to add item to index page in %u/%u/%u",
 				  data->node.spcNode, data->node.dbNode, data->node.relNode);
 			itup = (IndexTuple) (((char *) itup) + MAXALIGN(IndexTupleSize(itup)));
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 8c1015ae1b..68af1d57da 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -366,7 +366,7 @@ gistplacetopage(GISTInsertState *state, GISTSTATE *giststate)
 			data = (char *) (ptr->list);
 			for (i = 0; i < ptr->block.num; i++)
 			{
-				if (PageAddItem(ptr->page, (Item) data, IndexTupleSize((IndexTuple) data), i + FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
+				if (PageAddItem(ptr->page, (Item) data, IndexTupleSize((IndexTuple) data), i + FirstOffsetNumber, false) == InvalidOffsetNumber)
 					elog(ERROR, "failed to add item to index page in \"%s\"", RelationGetRelationName(state->r));
 				data += IndexTupleSize((IndexTuple) data);
 			}
diff --git a/src/backend/access/gist/gistget.c b/src/backend/access/gist/gistget.c
index f513c8dd16..ccd1425da8 100644
--- a/src/backend/access/gist/gistget.c
+++ b/src/backend/access/gist/gistget.c
@@ -46,7 +46,7 @@ killtuple(Relation r, GISTScanOpaque so, ItemPointer iptr)
 		{
 			/* page unchanged, so all is simple */
 			offset = ItemPointerGetOffsetNumber(iptr);
-			PageGetItemId(p, offset)->lp_flags |= LP_DELETE;
+			ItemIdMarkDead(PageGetItemId(p, offset));
 			SetBufferCommitInfoNeedsSave(buffer);
 			LockBuffer(buffer, GIST_UNLOCK);
 			break;
@@ -61,7 +61,7 @@ killtuple(Relation r, GISTScanOpaque so, ItemPointer iptr)
 			if (ItemPointerEquals(&(ituple->t_tid), iptr))
 			{
 				/* found */
-				PageGetItemId(p, offset)->lp_flags |= LP_DELETE;
+				ItemIdMarkDead(PageGetItemId(p, offset));
 				SetBufferCommitInfoNeedsSave(buffer);
 				LockBuffer(buffer, GIST_UNLOCK);
 				if (buffer != so->curbuf)
@@ -289,7 +289,7 @@ gistnext(IndexScanDesc scan, ScanDirection dir, ItemPointer tids,
 				ItemPointerSet(&(so->curpos),
 							   BufferGetBlockNumber(so->curbuf), n);
 
-				if (!(ignore_killed_tuples && ItemIdDeleted(PageGetItemId(p, n))))
+				if (!(ignore_killed_tuples && ItemIdIsDead(PageGetItemId(p, n))))
 				{
 					it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
 					tids[ntids] = scan->xs_ctup.t_self = it->t_tid;
diff --git a/src/backend/access/gist/gistutil.c b/src/backend/access/gist/gistutil.c
index e658d05928..1ddf0e97db 100644
--- a/src/backend/access/gist/gistutil.c
+++ b/src/backend/access/gist/gistutil.c
@@ -42,7 +42,7 @@ gistfillbuffer(Relation r, Page page, IndexTuple *itup,
 	for (i = 0; i < len; i++)
 	{
 		l = PageAddItem(page, (Item) itup[i], IndexTupleSize(itup[i]),
-						off, LP_USED);
+						off, false);
 		if (l == InvalidOffsetNumber)
 			elog(ERROR, "failed to add item to index page in \"%s\"",
 				 RelationGetRelationName(r));
diff --git a/src/backend/access/gist/gistvacuum.c b/src/backend/access/gist/gistvacuum.c
index eaa28a08b5..7bba2dbd63 100644
--- a/src/backend/access/gist/gistvacuum.c
+++ b/src/backend/access/gist/gistvacuum.c
@@ -201,7 +201,7 @@ vacuumSplitPage(GistVacuum *gv, Page tempPage, Buffer buffer, IndexTuple *addon,
 		data = (char *) (ptr->list);
 		for (i = 0; i < ptr->block.num; i++)
 		{
-			if (PageAddItem(ptr->page, (Item) data, IndexTupleSize((IndexTuple) data), i + FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
+			if (PageAddItem(ptr->page, (Item) data, IndexTupleSize((IndexTuple) data), i + FirstOffsetNumber, false) == InvalidOffsetNumber)
 				elog(ERROR, "failed to add item to index page in \"%s\"", RelationGetRelationName(gv->index));
 			data += IndexTupleSize((IndexTuple) data);
 		}
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 3fe3097201..dc5715a799 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -193,11 +193,11 @@ hashgettuple(PG_FUNCTION_ARGS)
 		if (scan->kill_prior_tuple)
 		{
 			/*
-			 * Yes, so mark it by setting the LP_DELETE bit in the item flags.
+			 * Yes, so mark it by setting the LP_DEAD state in the item flags.
 			 */
 			offnum = ItemPointerGetOffsetNumber(&(so->hashso_curpos));
 			page = BufferGetPage(so->hashso_curbuf);
-			PageGetItemId(page, offnum)->lp_flags |= LP_DELETE;
+			ItemIdMarkDead(PageGetItemId(page, offnum));
 
 			/*
 			 * Since this can be redone later if needed, it's treated the same
@@ -224,7 +224,7 @@ hashgettuple(PG_FUNCTION_ARGS)
 		{
 			offnum = ItemPointerGetOffsetNumber(&(so->hashso_curpos));
 			page = BufferGetPage(so->hashso_curbuf);
-			if (!ItemIdDeleted(PageGetItemId(page, offnum)))
+			if (!ItemIdIsDead(PageGetItemId(page, offnum)))
 				break;
 			res = _hash_next(scan, dir);
 		}
@@ -286,7 +286,7 @@ hashgetmulti(PG_FUNCTION_ARGS)
 
 				offnum = ItemPointerGetOffsetNumber(&(so->hashso_curpos));
 				page = BufferGetPage(so->hashso_curbuf);
-				if (!ItemIdDeleted(PageGetItemId(page, offnum)))
+				if (!ItemIdIsDead(PageGetItemId(page, offnum)))
 					break;
 				res = _hash_next(scan, ForwardScanDirection);
 			}
diff --git a/src/backend/access/hash/hashinsert.c b/src/backend/access/hash/hashinsert.c
index 10d91c2844..7d4d55f161 100644
--- a/src/backend/access/hash/hashinsert.c
+++ b/src/backend/access/hash/hashinsert.c
@@ -200,7 +200,7 @@ _hash_pgaddtup(Relation rel,
 	page = BufferGetPage(buf);
 
 	itup_off = OffsetNumberNext(PageGetMaxOffsetNumber(page));
-	if (PageAddItem(page, (Item) itup, itemsize, itup_off, LP_USED)
+	if (PageAddItem(page, (Item) itup, itemsize, itup_off, false)
 		== InvalidOffsetNumber)
 		elog(ERROR, "failed to add index item to \"%s\"",
 			 RelationGetRelationName(rel));
diff --git a/src/backend/access/hash/hashovfl.c b/src/backend/access/hash/hashovfl.c
index 70e705e110..b9ad162b25 100644
--- a/src/backend/access/hash/hashovfl.c
+++ b/src/backend/access/hash/hashovfl.c
@@ -684,7 +684,7 @@ _hash_squeezebucket(Relation rel,
 			 * we have found room so insert on the "write" page.
 			 */
 			woffnum = OffsetNumberNext(PageGetMaxOffsetNumber(wpage));
-			if (PageAddItem(wpage, (Item) itup, itemsz, woffnum, LP_USED)
+			if (PageAddItem(wpage, (Item) itup, itemsz, woffnum, false)
 				== InvalidOffsetNumber)
 				elog(ERROR, "failed to add index item to \"%s\"",
 					 RelationGetRelationName(rel));
diff --git a/src/backend/access/hash/hashpage.c b/src/backend/access/hash/hashpage.c
index 70d46f5d3e..b694e8800c 100644
--- a/src/backend/access/hash/hashpage.c
+++ b/src/backend/access/hash/hashpage.c
@@ -830,7 +830,7 @@ _hash_splitbucket(Relation rel,
 			}
 
 			noffnum = OffsetNumberNext(PageGetMaxOffsetNumber(npage));
-			if (PageAddItem(npage, (Item) itup, itemsz, noffnum, LP_USED)
+			if (PageAddItem(npage, (Item) itup, itemsz, noffnum, false)
 				== InvalidOffsetNumber)
 				elog(ERROR, "failed to add index item to \"%s\"",
 					 RelationGetRelationName(rel));
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index d77e64cd8b..9f1a7d6384 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -198,7 +198,7 @@ heapgetpage(HeapScanDesc scan, BlockNumber page)
 		 lineoff <= lines;
 		 lineoff++, lpp++)
 	{
-		if (ItemIdIsUsed(lpp))
+		if (ItemIdIsNormal(lpp))
 		{
 			HeapTupleData loctup;
 			bool		valid;
@@ -384,7 +384,7 @@ heapgettup(HeapScanDesc scan,
 	{
 		while (linesleft > 0)
 		{
-			if (ItemIdIsUsed(lpp))
+			if (ItemIdIsNormal(lpp))
 			{
 				bool		valid;
 
@@ -653,7 +653,7 @@ heapgettup_pagemode(HeapScanDesc scan,
 		{
 			lineoff = scan->rs_vistuples[lineindex];
 			lpp = PageGetItemId(dp, lineoff);
-			Assert(ItemIdIsUsed(lpp));
+			Assert(ItemIdIsNormal(lpp));
 
 			tuple->t_data = (HeapTupleHeader) PageGetItem((Page) dp, lpp);
 			tuple->t_len = ItemIdGetLength(lpp);
@@ -1334,7 +1334,7 @@ heap_release_fetch(Relation relation,
 	/*
 	 * Must check for deleted tuple.
 	 */
-	if (!ItemIdIsUsed(lp))
+	if (!ItemIdIsNormal(lp))
 	{
 		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
 		if (keep_buf)
@@ -1463,7 +1463,7 @@ heap_get_latest_tid(Relation relation,
 			break;
 		}
 		lp = PageGetItemId(dp, offnum);
-		if (!ItemIdIsUsed(lp))
+		if (!ItemIdIsNormal(lp))
 		{
 			UnlockReleaseBuffer(buffer);
 			break;
@@ -1775,6 +1775,7 @@ heap_delete(Relation relation, ItemPointer tid,
 
 	dp = (PageHeader) BufferGetPage(buffer);
 	lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
+	Assert(ItemIdIsNormal(lp));
 
 	tp.t_data = (HeapTupleHeader) PageGetItem(dp, lp);
 	tp.t_len = ItemIdGetLength(lp);
@@ -2079,6 +2080,7 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 
 	dp = (PageHeader) BufferGetPage(buffer);
 	lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(otid));
+	Assert(ItemIdIsNormal(lp));
 
 	oldtup.t_data = (HeapTupleHeader) PageGetItem(dp, lp);
 	oldtup.t_len = ItemIdGetLength(lp);
@@ -2565,7 +2567,7 @@ heap_lock_tuple(Relation relation, HeapTuple tuple, Buffer *buffer,
 
 	dp = (PageHeader) BufferGetPage(*buffer);
 	lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
-	Assert(ItemIdIsUsed(lp));
+	Assert(ItemIdIsNormal(lp));
 
 	tuple->t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp);
 	tuple->t_len = ItemIdGetLength(lp);
@@ -2958,7 +2960,7 @@ heap_inplace_update(Relation relation, HeapTuple tuple)
 	if (PageGetMaxOffsetNumber(page) >= offnum)
 		lp = PageGetItemId(page, offnum);
 
-	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsUsed(lp))
+	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
 		elog(ERROR, "heap_inplace_update: invalid lp");
 
 	htup = (HeapTupleHeader) PageGetItem(page, lp);
@@ -3523,7 +3525,7 @@ heap_xlog_clean(XLogRecPtr lsn, XLogRecord *record)
 		{
 			/* unused[] entries are zero-based */
 			lp = PageGetItemId(page, *unused + 1);
-			lp->lp_flags &= ~LP_USED;
+			ItemIdSetUnused(lp);
 			unused++;
 		}
 	}
@@ -3643,7 +3645,7 @@ heap_xlog_delete(XLogRecPtr lsn, XLogRecord *record)
 	if (PageGetMaxOffsetNumber(page) >= offnum)
 		lp = PageGetItemId(page, offnum);
 
-	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsUsed(lp))
+	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
 		elog(PANIC, "heap_delete_redo: invalid lp");
 
 	htup = (HeapTupleHeader) PageGetItem(page, lp);
@@ -3734,8 +3736,7 @@ heap_xlog_insert(XLogRecPtr lsn, XLogRecord *record)
 	HeapTupleHeaderSetCmin(htup, FirstCommandId);
 	htup->t_ctid = xlrec->target.tid;
 
-	offnum = PageAddItem(page, (Item) htup, newlen, offnum,
-						 LP_USED | OverwritePageMode);
+	offnum = PageAddItem(page, (Item) htup, newlen, offnum, true);
 	if (offnum == InvalidOffsetNumber)
 		elog(PANIC, "heap_insert_redo: failed to add tuple");
 	PageSetLSN(page, lsn);
@@ -3796,7 +3797,7 @@ heap_xlog_update(XLogRecPtr lsn, XLogRecord *record, bool move)
 	if (PageGetMaxOffsetNumber(page) >= offnum)
 		lp = PageGetItemId(page, offnum);
 
-	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsUsed(lp))
+	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
 		elog(PANIC, "heap_update_redo: invalid lp");
 
 	htup = (HeapTupleHeader) PageGetItem(page, lp);
@@ -3913,8 +3914,7 @@ newsame:;
 	/* Make sure there is no forward chain link in t_ctid */
 	htup->t_ctid = xlrec->newtid;
 
-	offnum = PageAddItem(page, (Item) htup, newlen, offnum,
-						 LP_USED | OverwritePageMode);
+	offnum = PageAddItem(page, (Item) htup, newlen, offnum, true);
 	if (offnum == InvalidOffsetNumber)
 		elog(PANIC, "heap_update_redo: failed to add tuple");
 	PageSetLSN(page, lsn);
@@ -3955,7 +3955,7 @@ heap_xlog_lock(XLogRecPtr lsn, XLogRecord *record)
 	if (PageGetMaxOffsetNumber(page) >= offnum)
 		lp = PageGetItemId(page, offnum);
 
-	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsUsed(lp))
+	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
 		elog(PANIC, "heap_lock_redo: invalid lp");
 
 	htup = (HeapTupleHeader) PageGetItem(page, lp);
@@ -4014,7 +4014,7 @@ heap_xlog_inplace(XLogRecPtr lsn, XLogRecord *record)
 	if (PageGetMaxOffsetNumber(page) >= offnum)
 		lp = PageGetItemId(page, offnum);
 
-	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsUsed(lp))
+	if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp))
 		elog(PANIC, "heap_inplace_redo: invalid lp");
 
 	htup = (HeapTupleHeader) PageGetItem(page, lp);
diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c
index c8eedefbdc..fa8a2afbba 100644
--- a/src/backend/access/heap/hio.c
+++ b/src/backend/access/heap/hio.c
@@ -41,7 +41,7 @@ RelationPutHeapTuple(Relation relation,
 	pageHeader = BufferGetPage(buffer);
 
 	offnum = PageAddItem(pageHeader, (Item) tuple->t_data,
-						 tuple->t_len, InvalidOffsetNumber, LP_USED);
+						 tuple->t_len, InvalidOffsetNumber, false);
 
 	if (offnum == InvalidOffsetNumber)
 		elog(PANIC, "failed to add tuple to page");
diff --git a/src/backend/access/heap/rewriteheap.c b/src/backend/access/heap/rewriteheap.c
index 314f01ed75..e4578ea3aa 100644
--- a/src/backend/access/heap/rewriteheap.c
+++ b/src/backend/access/heap/rewriteheap.c
@@ -628,7 +628,7 @@ raw_heap_insert(RewriteState state, HeapTuple tup)
 
 	/* And now we can insert the tuple into the page */
 	newoff = PageAddItem(page, (Item) heaptup->t_data, len,
-						 InvalidOffsetNumber, LP_USED);
+						 InvalidOffsetNumber, false);
 	if (newoff == InvalidOffsetNumber)
 		elog(ERROR, "failed to add tuple");
 
diff --git a/src/backend/access/nbtree/README b/src/backend/access/nbtree/README
index 412abed2e6..f9bd756394 100644
--- a/src/backend/access/nbtree/README
+++ b/src/backend/access/nbtree/README
@@ -327,17 +327,17 @@ If a process visits a heap tuple and finds that it's dead and removable
 (ie, dead to all open transactions, not only that process), then we can
 return to the index and mark the corresponding index entry "known dead",
 allowing subsequent index scans to skip visiting the heap tuple.  The
-"known dead" marking uses the LP_DELETE bit in ItemIds.  This is currently
-only done in plain indexscans, not bitmap scans, because only plain scans
-visit the heap and index "in sync" and so there's not a convenient way
-to do it for bitmap scans.
+"known dead" marking works by setting the index item's lp_flags state
+to LP_DEAD.  This is currently only done in plain indexscans, not bitmap
+scans, because only plain scans visit the heap and index "in sync" and so
+there's not a convenient way to do it for bitmap scans.
 
-Once an index tuple has been marked LP_DELETE it can actually be removed
+Once an index tuple has been marked LP_DEAD it can actually be removed
 from the index immediately; since index scans only stop "between" pages,
 no scan can lose its place from such a deletion.  We separate the steps
-because we allow LP_DELETE to be set with only a share lock (it's exactly
+because we allow LP_DEAD to be set with only a share lock (it's exactly
 like a hint bit for a heap tuple), but physically removing tuples requires
-exclusive lock.  In the current code we try to remove LP_DELETE tuples when
+exclusive lock.  In the current code we try to remove LP_DEAD tuples when
 we are otherwise faced with having to split a page to do an insertion (and
 hence have exclusive lock on it already).
 
@@ -349,7 +349,7 @@ same situation is created by REINDEX, since it doesn't enter dead
 tuples into the index.)
 
 It's sufficient to have an exclusive lock on the index page, not a
-super-exclusive lock, to do deletion of LP_DELETE items.  It might seem
+super-exclusive lock, to do deletion of LP_DEAD items.  It might seem
 that this breaks the interlock between VACUUM and indexscans, but that is
 not so: as long as an indexscanning process has a pin on the page where
 the index item used to be, VACUUM cannot complete its btbulkdelete scan
diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index a8ebe688a2..8f8f7b63b4 100644
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -221,7 +221,7 @@ _bt_check_unique(Relation rel, IndexTuple itup, Relation heapRel,
 			 * we can. We only apply _bt_isequal() when we get to a non-killed
 			 * item or the end of the page.
 			 */
-			if (!ItemIdDeleted(curitemid))
+			if (!ItemIdIsDead(curitemid))
 			{
 				/*
 				 * _bt_compare returns 0 for (1,NULL) and (1,NULL) - this's
@@ -301,7 +301,7 @@ _bt_check_unique(Relation rel, IndexTuple itup, Relation heapRel,
 					if (HeapTupleSatisfiesVacuum(htup.t_data, RecentGlobalXmin,
 												 hbuffer) == HEAPTUPLE_DEAD)
 					{
-						curitemid->lp_flags |= LP_DELETE;
+						ItemIdMarkDead(curitemid);
 						opaque->btpo_flags |= BTP_HAS_GARBAGE;
 						/* be sure to mark the proper buffer dirty... */
 						if (nbuf != InvalidBuffer)
@@ -368,7 +368,7 @@ _bt_check_unique(Relation rel, IndexTuple itup, Relation heapRel,
  *		any existing equal keys because of the way _bt_binsrch() works.
  *
  *		If there's not enough room in the space, we try to make room by
- *		removing any LP_DELETEd tuples.
+ *		removing any LP_DEAD tuples.
  *
  *		On entry, *buf and *offsetptr point to the first legal position
  *		where the new tuple could be inserted. The caller should hold an
@@ -449,7 +449,7 @@ _bt_findinsertloc(Relation rel,
 
 		/*
 		 * before considering moving right, see if we can obtain enough
-		 * space by erasing LP_DELETE items
+		 * space by erasing LP_DEAD items
 		 */
 		if (P_ISLEAF(lpageop) && P_HAS_GARBAGE(lpageop))
 		{
@@ -840,7 +840,7 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
 		itemsz = ItemIdGetLength(itemid);
 		item = (IndexTuple) PageGetItem(origpage, itemid);
 		if (PageAddItem(rightpage, (Item) item, itemsz, rightoff,
-						LP_USED) == InvalidOffsetNumber)
+						false) == InvalidOffsetNumber)
 			elog(PANIC, "failed to add hikey to the right sibling");
 		rightoff = OffsetNumberNext(rightoff);
 	}
@@ -865,7 +865,7 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
 		item = (IndexTuple) PageGetItem(origpage, itemid);
 	}
 	if (PageAddItem(leftpage, (Item) item, itemsz, leftoff,
-					LP_USED) == InvalidOffsetNumber)
+					false) == InvalidOffsetNumber)
 		elog(PANIC, "failed to add hikey to the left sibling");
 	leftoff = OffsetNumberNext(leftoff);
 
@@ -1699,7 +1699,8 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf)
 	 * Note: we *must* insert the two items in item-number order, for the
 	 * benefit of _bt_restore_page().
 	 */
-	if (PageAddItem(rootpage, (Item) new_item, itemsz, P_HIKEY, LP_USED) == InvalidOffsetNumber)
+	if (PageAddItem(rootpage, (Item) new_item, itemsz, P_HIKEY,
+					false) == InvalidOffsetNumber)
 		elog(PANIC, "failed to add leftkey to new root page");
 	pfree(new_item);
 
@@ -1716,7 +1717,8 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf)
 	/*
 	 * insert the right page pointer into the new root page.
 	 */
-	if (PageAddItem(rootpage, (Item) new_item, itemsz, P_FIRSTKEY, LP_USED) == InvalidOffsetNumber)
+	if (PageAddItem(rootpage, (Item) new_item, itemsz, P_FIRSTKEY,
+					false) == InvalidOffsetNumber)
 		elog(PANIC, "failed to add rightkey to new root page");
 	pfree(new_item);
 
@@ -1803,7 +1805,7 @@ _bt_pgaddtup(Relation rel,
 	}
 
 	if (PageAddItem(page, (Item) itup, itemsize, itup_off,
-					LP_USED) == InvalidOffsetNumber)
+					false) == InvalidOffsetNumber)
 		elog(PANIC, "failed to add item to the %s for \"%s\"",
 			 where, RelationGetRelationName(rel));
 }
@@ -1858,7 +1860,7 @@ _bt_isequal(TupleDesc itupdesc, Page page, OffsetNumber offnum,
 /*
  * _bt_vacuum_one_page - vacuum just one index page.
  *
- * Try to remove LP_DELETE items from the given page.  The passed buffer
+ * Try to remove LP_DEAD items from the given page.  The passed buffer
  * must be exclusive-locked, but unlike a real VACUUM, we don't need a
  * super-exclusive "cleanup" lock (see nbtree/README).
  */
@@ -1875,7 +1877,7 @@ _bt_vacuum_one_page(Relation rel, Buffer buffer)
 
 	/*
 	 * Scan over all items to see which ones need to be deleted
-	 * according to LP_DELETE flags.
+	 * according to LP_DEAD flags.
 	 */
 	minoff = P_FIRSTDATAKEY(opaque);
 	maxoff = PageGetMaxOffsetNumber(page);
@@ -1885,7 +1887,7 @@ _bt_vacuum_one_page(Relation rel, Buffer buffer)
 	{
 		ItemId		itemId = PageGetItemId(page, offnum);
 
-		if (ItemIdDeleted(itemId))
+		if (ItemIdIsDead(itemId))
 			deletable[ndeletable++] = offnum;
 	}
 
@@ -1893,7 +1895,7 @@ _bt_vacuum_one_page(Relation rel, Buffer buffer)
 		_bt_delitems(rel, buffer, deletable, ndeletable);
 
 	/*
-	 * Note: if we didn't find any LP_DELETE items, then the page's
+	 * Note: if we didn't find any LP_DEAD items, then the page's
 	 * BTP_HAS_GARBAGE hint bit is falsely set.  We do not bother expending a
 	 * separate write to clear it, however.  We will clear it when we split
 	 * the page.
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index 0821a13ff0..2c7a834adc 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -669,7 +669,7 @@ _bt_delitems(Relation rel, Buffer buf,
 	opaque->btpo_cycleid = 0;
 
 	/*
-	 * Mark the page as not containing any LP_DELETE items.  This is not
+	 * Mark the page as not containing any LP_DEAD items.  This is not
 	 * certainly true (there might be some that have recently been marked, but
 	 * weren't included in our target-item list), but it will almost always be
 	 * true and it doesn't seem worth an additional page scan to check it.
diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c
index 87e6da59ef..bacf52d48b 100644
--- a/src/backend/access/nbtree/nbtsort.c
+++ b/src/backend/access/nbtree/nbtsort.c
@@ -400,7 +400,7 @@ _bt_sortaddtup(Page page,
 	}
 
 	if (PageAddItem(page, (Item) itup, itemsize, itup_off,
-					LP_USED) == InvalidOffsetNumber)
+					false) == InvalidOffsetNumber)
 		elog(ERROR, "failed to add item to the index page");
 }
 
@@ -521,7 +521,7 @@ _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup)
 		 */
 		hii = PageGetItemId(opage, P_HIKEY);
 		*hii = *ii;
-		ii->lp_flags &= ~LP_USED;
+		ItemIdSetUnused(ii);	/* redundant */
 		((PageHeader) opage)->pd_lower -= sizeof(ItemIdData);
 
 		/*
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index d6c1ee501c..a0e115d533 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -789,7 +789,7 @@ _bt_checkkeys(IndexScanDesc scan,
 	 * However, if this is the last tuple on the page, we should check the
 	 * index keys to prevent uselessly advancing to the next page.
 	 */
-	if (scan->ignore_killed_tuples && ItemIdDeleted(iid))
+	if (scan->ignore_killed_tuples && ItemIdIsDead(iid))
 	{
 		/* return immediately if there are more tuples on the page */
 		if (ScanDirectionIsForward(dir))
@@ -1088,7 +1088,7 @@ _bt_check_rowcompare(ScanKey skey, IndexTuple tuple, TupleDesc tupdesc,
 }
 
 /*
- * _bt_killitems - set LP_DELETE bit for items an indexscan caller has
+ * _bt_killitems - set LP_DEAD state for items an indexscan caller has
  * told us were killed
  *
  * scan->so contains information about the current page and killed tuples
@@ -1096,7 +1096,7 @@ _bt_check_rowcompare(ScanKey skey, IndexTuple tuple, TupleDesc tupdesc,
  *
  * The caller must have pin on so->currPos.buf, but may or may not have
  * read-lock, as indicated by haveLock.  Note that we assume read-lock
- * is sufficient for setting LP_DELETE hint bits.
+ * is sufficient for setting LP_DEAD status (which is only a hint).
  *
  * We match items by heap TID before assuming they are the right ones to
  * delete.	We cope with cases where items have moved right due to insertions.
@@ -1149,7 +1149,7 @@ _bt_killitems(IndexScanDesc scan, bool haveLock)
 			if (ItemPointerEquals(&ituple->t_tid, &kitem->heapTid))
 			{
 				/* found the item */
-				iid->lp_flags |= LP_DELETE;
+				ItemIdMarkDead(iid);
 				killedsomething = true;
 				break;			/* out of inner search loop */
 			}
@@ -1162,7 +1162,7 @@ _bt_killitems(IndexScanDesc scan, bool haveLock)
 	 * commit-hint-bit status update for heap tuples: we mark the buffer dirty
 	 * but don't make a WAL log entry.
 	 *
-	 * Whenever we mark anything LP_DELETEd, we also set the page's
+	 * Whenever we mark anything LP_DEAD, we also set the page's
 	 * BTP_HAS_GARBAGE flag, which is likewise just a hint.
 	 */
 	if (killedsomething)
diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index 0c09ee8d44..ab0c37caa6 100644
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -142,7 +142,7 @@ _bt_restore_page(Page page, char *from, int len)
 		itemsz = IndexTupleDSize(itupdata);
 		itemsz = MAXALIGN(itemsz);
 		if (PageAddItem(page, (Item) from, itemsz,
-						FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
+						FirstOffsetNumber, false) == InvalidOffsetNumber)
 			elog(PANIC, "_bt_restore_page: cannot add item to page");
 		from += itemsz;
 	}
@@ -238,7 +238,7 @@ btree_xlog_insert(bool isleaf, bool ismeta,
 			{
 				if (PageAddItem(page, (Item) datapos, datalen,
 							ItemPointerGetOffsetNumber(&(xlrec->target.tid)),
-								LP_USED) == InvalidOffsetNumber)
+								false) == InvalidOffsetNumber)
 					elog(PANIC, "btree_insert_redo: failed to add item");
 
 				PageSetLSN(page, lsn);
@@ -389,7 +389,7 @@ btree_xlog_split(bool onleft, bool isroot,
 				if (onleft)
 				{
 					if (PageAddItem(lpage, newitem, newitemsz, newitemoff,
-									LP_USED) == InvalidOffsetNumber)
+									false) == InvalidOffsetNumber)
 						elog(PANIC, "failed to add new item to left page after split");
 				}
 
@@ -398,7 +398,7 @@ btree_xlog_split(bool onleft, bool isroot,
 				hiItem = PageGetItem(rpage, hiItemId);
 
 				if (PageAddItem(lpage, hiItem, ItemIdGetLength(hiItemId),
-								P_HIKEY, LP_USED) == InvalidOffsetNumber)
+								P_HIKEY, false) == InvalidOffsetNumber)
 					elog(PANIC, "failed to add high key to left page after split");
 
 				/* Fix opaque fields */
@@ -483,7 +483,7 @@ btree_xlog_delete(XLogRecPtr lsn, XLogRecord *record)
 	}
 
 	/*
-	 * Mark the page as not containing any LP_DELETE items --- see comments in
+	 * Mark the page as not containing any LP_DEAD items --- see comments in
 	 * _bt_delitems().
 	 */
 	opaque = (BTPageOpaque) PageGetSpecialPointer(page);
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 662b12135a..bdee553bca 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -936,7 +936,7 @@ read_info(SeqTable elm, Relation rel, Buffer *buf)
 			 RelationGetRelationName(rel), sm->magic);
 
 	lp = PageGetItemId(page, FirstOffsetNumber);
-	Assert(ItemIdIsUsed(lp));
+	Assert(ItemIdIsNormal(lp));
 	tuple.t_data = (HeapTupleHeader) PageGetItem((Page) page, lp);
 
 	seq = (Form_pg_sequence) GETSTRUCT(&tuple);
@@ -1281,7 +1281,7 @@ seq_redo(XLogRecPtr lsn, XLogRecord *record)
 	itemsz = record->xl_len - sizeof(xl_seq_rec);
 	itemsz = MAXALIGN(itemsz);
 	if (PageAddItem(page, (Item) item, itemsz,
-					FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
+					FirstOffsetNumber, false) == InvalidOffsetNumber)
 		elog(PANIC, "seq_redo: failed to add item to page");
 
 	PageSetLSN(page, lsn);
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 1551ee2eb4..9e517dfaa0 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -1826,7 +1826,7 @@ ltrmark:;
 		dp = (PageHeader) BufferGetPage(buffer);
 		lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
 
-		Assert(ItemIdIsUsed(lp));
+		Assert(ItemIdIsNormal(lp));
 
 		tuple.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp);
 		tuple.t_len = ItemIdGetLength(lp);
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index ac60c110b8..81083ea604 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -1522,7 +1522,7 @@ scan_heap(VRelStats *vacrelstats, Relation onerel,
 
 				/* mark it unused on the temp page */
 				lpp = PageGetItemId(tempPage, offnum);
-				lpp->lp_flags &= ~LP_USED;
+				ItemIdSetUnused(lpp);
 
 				vacpage->offsets[vacpage->offsets_free++] = offnum;
 				tups_vacuumed += 1;
@@ -1558,7 +1558,7 @@ scan_heap(VRelStats *vacrelstats, Relation onerel,
 		{
 			/* Just use current available space */
 			vacpage->free = PageGetFreeSpaceWithFillFactor(onerel, page);
-			/* Need to reap the page if it has ~LP_USED line pointers */
+			/* Need to reap the page if it has LP_UNUSED line pointers */
 			do_reap = (vacpage->offsets_free > 0);
 		}
 
@@ -2582,7 +2582,7 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 				if (HeapTupleHeaderGetXvac(htup) != myXID)
 					elog(ERROR, "invalid XVAC in tuple header");
 
-				itemid->lp_flags &= ~LP_USED;
+				ItemIdSetUnused(itemid);
 				num_tuples++;
 			}
 			Assert(vacpage->offsets_free == num_tuples);
@@ -2714,7 +2714,7 @@ move_chain_tuple(Relation rel,
 	newtup.t_data->t_infomask |= HEAP_MOVED_IN;
 	HeapTupleHeaderSetXvac(newtup.t_data, myXID);
 	newoff = PageAddItem(dst_page, (Item) newtup.t_data, tuple_len,
-						 InvalidOffsetNumber, LP_USED);
+						 InvalidOffsetNumber, false);
 	if (newoff == InvalidOffsetNumber)
 		elog(PANIC, "failed to add item with len = %lu to page %u while moving tuple chain",
 			 (unsigned long) tuple_len, dst_vacpage->blkno);
@@ -2819,7 +2819,7 @@ move_plain_tuple(Relation rel,
 
 	/* add tuple to the page */
 	newoff = PageAddItem(dst_page, (Item) newtup.t_data, tuple_len,
-						 InvalidOffsetNumber, LP_USED);
+						 InvalidOffsetNumber, false);
 	if (newoff == InvalidOffsetNumber)
 		elog(PANIC, "failed to add item with len = %lu to page %u (free space %lu, nusd %u, noff %u)",
 			 (unsigned long) tuple_len,
@@ -3033,7 +3033,7 @@ vacuum_page(Relation onerel, Buffer buffer, VacPage vacpage)
 	for (i = 0; i < vacpage->offsets_free; i++)
 	{
 		itemid = PageGetItemId(page, vacpage->offsets[i]);
-		itemid->lp_flags &= ~LP_USED;
+		ItemIdSetUnused(itemid);
 	}
 
 	uncnt = PageRepairFragmentation(page, unused);
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 22d7fea211..2911856a3d 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -642,7 +642,7 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 			break;				/* past end of tuples for this block */
 		toff = ItemPointerGetOffsetNumber(&vacrelstats->dead_tuples[tupindex]);
 		itemid = PageGetItemId(page, toff);
-		itemid->lp_flags &= ~LP_USED;
+		ItemIdSetUnused(itemid);
 	}
 
 	uncnt = PageRepairFragmentation(page, unused);
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 6c42fd3b32..c830e82f14 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -183,7 +183,7 @@ BitmapHeapNext(BitmapHeapScanState *node)
 		targoffset = scan->rs_vistuples[scan->rs_cindex];
 		dp = (Page) BufferGetPage(scan->rs_cbuf);
 		lp = PageGetItemId(dp, targoffset);
-		Assert(ItemIdIsUsed(lp));
+		Assert(ItemIdIsNormal(lp));
 
 		scan->rs_ctup.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp);
 		scan->rs_ctup.t_len = ItemIdGetLength(lp);
@@ -317,7 +317,7 @@ bitgetpage(HeapScanDesc scan, TBMIterateResult *tbmres)
 		/*
 		 * Must check for deleted tuple.
 		 */
-		if (!ItemIdIsUsed(lp))
+		if (!ItemIdIsNormal(lp))
 			continue;
 
 		/*
diff --git a/src/backend/storage/page/bufpage.c b/src/backend/storage/page/bufpage.c
index b63a191829..b90ee8fd93 100644
--- a/src/backend/storage/page/bufpage.c
+++ b/src/backend/storage/page/bufpage.c
@@ -99,7 +99,10 @@ PageHeaderIsValid(PageHeader page)
  *	Add an item to a page.	Return value is offset at which it was
  *	inserted, or InvalidOffsetNumber if there's not room to insert.
  *
- *	If offsetNumber is valid and <= current max offset in the page,
+ *	If overwrite is true, we just store the item at the specified
+ *	offsetNumber (which must be either a currently-unused item pointer,
+ *	or one past the last existing item).  Otherwise,
+ *	if offsetNumber is valid and <= current max offset in the page,
  *	insert item into the array at that position by shuffling ItemId's
  *	down to make room.
  *	If offsetNumber is not valid, then assign one by finding the first
@@ -112,7 +115,7 @@ PageAddItem(Page page,
 			Item item,
 			Size size,
 			OffsetNumber offsetNumber,
-			ItemIdFlags flags)
+			bool overwrite)
 {
 	PageHeader	phdr = (PageHeader) page;
 	Size		alignedSize;
@@ -121,9 +124,6 @@ PageAddItem(Page page,
 	ItemId		itemId;
 	OffsetNumber limit;
 	bool		needshuffle = false;
-	bool		overwritemode = (flags & OverwritePageMode) != 0;
-
-	flags &= ~OverwritePageMode;
 
 	/*
 	 * Be wary about corrupted page pointers
@@ -146,12 +146,12 @@ PageAddItem(Page page,
 	if (OffsetNumberIsValid(offsetNumber))
 	{
 		/* yes, check it */
-		if (overwritemode)
+		if (overwrite)
 		{
 			if (offsetNumber < limit)
 			{
 				itemId = PageGetItemId(phdr, offsetNumber);
-				if (ItemIdIsUsed(itemId) || ItemIdGetLength(itemId) != 0)
+				if (ItemIdIsUsed(itemId) || ItemIdHasStorage(itemId))
 				{
 					elog(WARNING, "will not overwrite a used ItemId");
 					return InvalidOffsetNumber;
@@ -170,11 +170,15 @@ PageAddItem(Page page,
 		/* if no free slot, we'll put it at limit (1st open slot) */
 		if (PageHasFreeLinePointers(phdr))
 		{
-			/* look for "recyclable" (unused & deallocated) ItemId */
+			/*
+			 * Look for "recyclable" (unused) ItemId.  We check for no
+			 * storage as well, just to be paranoid --- unused items
+			 * should never have storage.
+			 */
 			for (offsetNumber = 1; offsetNumber < limit; offsetNumber++)
 			{
 				itemId = PageGetItemId(phdr, offsetNumber);
-				if (!ItemIdIsUsed(itemId) && ItemIdGetLength(itemId) == 0)
+				if (!ItemIdIsUsed(itemId) && !ItemIdHasStorage(itemId))
 					break;
 			}
 			if (offsetNumber >= limit)
@@ -224,9 +228,7 @@ PageAddItem(Page page,
 				(limit - offsetNumber) * sizeof(ItemIdData));
 
 	/* set the item pointer */
-	itemId->lp_off = upper;
-	itemId->lp_len = size;
-	itemId->lp_flags = flags;
+	ItemIdSetNormal(itemId, upper, size);
 
 	/* copy the item's data onto the page */
 	memcpy((char *) page + upper, item, size);
@@ -326,6 +328,7 @@ PageRepairFragmentation(Page page, OffsetNumber *unused)
 				itemidptr;
 	ItemId		lp;
 	int			nline,
+				nstorage,
 				nused;
 	int			i;
 	Size		totallen;
@@ -349,38 +352,41 @@ PageRepairFragmentation(Page page, OffsetNumber *unused)
 						pd_lower, pd_upper, pd_special)));
 
 	nline = PageGetMaxOffsetNumber(page);
-	nused = 0;
+	nused = nstorage = 0;
 	for (i = 0; i < nline; i++)
 	{
 		lp = PageGetItemId(page, i + 1);
-		if (ItemIdDeleted(lp))	/* marked for deletion */
-			lp->lp_flags &= ~(LP_USED | LP_DELETE);
 		if (ItemIdIsUsed(lp))
+		{
 			nused++;
-		else if (unused)
-			unused[i - nused] = (OffsetNumber) i;
+			if (ItemIdHasStorage(lp))
+				nstorage++;
+		}
+		else
+		{
+			/* Unused entries should have lp_len = 0, but make sure */
+			ItemIdSetUnused(lp);
+			/* Report to caller if asked for */
+			if (unused)
+				unused[i - nused] = (OffsetNumber) i;
+		}
 	}
 
-	if (nused == 0)
+	if (nstorage == 0)
 	{
 		/* Page is completely empty, so just reset it quickly */
-		for (i = 0; i < nline; i++)
-		{
-			lp = PageGetItemId(page, i + 1);
-			lp->lp_len = 0;		/* indicate unused & deallocated */
-		}
 		((PageHeader) page)->pd_upper = pd_special;
 	}
 	else
-	{							/* nused != 0 */
+	{							/* nstorage != 0 */
 		/* Need to compact the page the hard way */
-		itemidbase = (itemIdSort) palloc(sizeof(itemIdSortData) * nused);
+		itemidbase = (itemIdSort) palloc(sizeof(itemIdSortData) * nstorage);
 		itemidptr = itemidbase;
 		totallen = 0;
 		for (i = 0; i < nline; i++)
 		{
 			lp = PageGetItemId(page, i + 1);
-			if (ItemIdIsUsed(lp))
+			if (ItemIdHasStorage(lp))
 			{
 				itemidptr->offsetindex = i;
 				itemidptr->itemoff = ItemIdGetOffset(lp);
@@ -394,10 +400,6 @@ PageRepairFragmentation(Page page, OffsetNumber *unused)
 				totallen += itemidptr->alignedlen;
 				itemidptr++;
 			}
-			else
-			{
-				lp->lp_len = 0; /* indicate unused & deallocated */
-			}
 		}
 
 		if (totallen > (Size) (pd_special - pd_lower))
@@ -407,13 +409,13 @@ PageRepairFragmentation(Page page, OffsetNumber *unused)
 					  (unsigned int) totallen, pd_special - pd_lower)));
 
 		/* sort itemIdSortData array into decreasing itemoff order */
-		qsort((char *) itemidbase, nused, sizeof(itemIdSortData),
+		qsort((char *) itemidbase, nstorage, sizeof(itemIdSortData),
 			  itemoffcompare);
 
 		/* compactify page */
 		upper = pd_special;
 
-		for (i = 0, itemidptr = itemidbase; i < nused; i++, itemidptr++)
+		for (i = 0, itemidptr = itemidbase; i < nstorage; i++, itemidptr++)
 		{
 			lp = PageGetItemId(page, itemidptr->offsetindex + 1);
 			upper -= itemidptr->alignedlen;
@@ -520,6 +522,7 @@ PageIndexTupleDelete(Page page, OffsetNumber offnum)
 	offidx = offnum - 1;
 
 	tup = PageGetItemId(page, offnum);
+	Assert(ItemIdHasStorage(tup));
 	size = ItemIdGetLength(tup);
 	offset = ItemIdGetOffset(tup);
 
@@ -577,6 +580,7 @@ PageIndexTupleDelete(Page page, OffsetNumber offnum)
 		{
 			ItemId		ii = PageGetItemId(phdr, i);
 
+			Assert(ItemIdHasStorage(ii));
 			if (ItemIdGetOffset(ii) <= offset)
 				ii->lp_off += size;
 		}
@@ -654,6 +658,7 @@ PageIndexMultiDelete(Page page, OffsetNumber *itemnos, int nitems)
 	for (offnum = 1; offnum <= nline; offnum++)
 	{
 		lp = PageGetItemId(page, offnum);
+		Assert(ItemIdHasStorage(lp));
 		size = ItemIdGetLength(lp);
 		offset = ItemIdGetOffset(lp);
 		if (offset < pd_upper ||
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index deb6247714..786714806b 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -137,7 +137,7 @@ typedef PageHeaderData *PageHeader;
  * pd_flags contains the following flag bits.  Undefined bits are initialized
  * to zero and may be used in the future.
  *
- * PD_HAS_FREE_LINES is set if there are any not-LP_USED line pointers before
+ * PD_HAS_FREE_LINES is set if there are any LP_UNUSED line pointers before
  * pd_lower.  This should be considered a hint rather than the truth, since
  * changes to it are not WAL-logged.
  */
@@ -274,7 +274,7 @@ typedef PageHeaderData *PageHeader;
 #define PageGetItem(page, itemId) \
 ( \
 	AssertMacro(PageIsValid(page)), \
-	AssertMacro(ItemIdIsUsed(itemId)), \
+	AssertMacro(ItemIdHasStorage(itemId)), \
 	(Item)(((char *)(page)) + ItemIdGetOffset(itemId)) \
 )
 
@@ -346,7 +346,7 @@ typedef PageHeaderData *PageHeader;
 extern void PageInit(Page page, Size pageSize, Size specialSize);
 extern bool PageHeaderIsValid(PageHeader page);
 extern OffsetNumber PageAddItem(Page page, Item item, Size size,
-			OffsetNumber offsetNumber, ItemIdFlags flags);
+			OffsetNumber offsetNumber, bool overwrite);
 extern Page PageGetTempPage(Page page, Size specialSize);
 extern void PageRestoreTempPage(Page tempPage, Page oldPage);
 extern int	PageRepairFragmentation(Page page, OffsetNumber *unused);
diff --git a/src/include/storage/itemid.h b/src/include/storage/itemid.h
index 5dbae48071..d18bb0d7bc 100644
--- a/src/include/storage/itemid.h
+++ b/src/include/storage/itemid.h
@@ -16,41 +16,36 @@
 
 /*
  * An item pointer (also called line pointer) on a buffer page
+ *
+ * In some cases an item pointer is "in use" but does not have any associated
+ * storage on the page.  By convention, lp_len == 0 in every item pointer
+ * that does not have storage, independently of its lp_flags state.
  */
 typedef struct ItemIdData
-{								/* line pointers */
-	unsigned	lp_off:15,		/* offset to start of tuple */
-				lp_flags:2,		/* flags for tuple */
-				lp_len:15;		/* length of tuple */
+{
+	unsigned	lp_off:15,		/* offset to tuple (from start of page) */
+				lp_flags:2,		/* state of item pointer, see below */
+				lp_len:15;		/* byte length of tuple */
 } ItemIdData;
 
 typedef ItemIdData *ItemId;
 
 /*
- * lp_flags contains these flags:
- */
-#define LP_USED			0x01	/* this line pointer is being used */
-
-#define LP_DELETE		0x02	/* item is to be deleted */
-
-#define ItemIdDeleted(itemId) \
-	(((itemId)->lp_flags & LP_DELETE) != 0)
-
-/*
- * This bit may be passed to PageAddItem together with
- * LP_USED & LP_DELETE bits to specify overwrite mode
+ * lp_flags has these possible states.  An UNUSED line pointer is available
+ * for immediate re-use, the other states are not.
  */
-#define OverwritePageMode	0x10
+#define LP_UNUSED		0		/* unused (should always have lp_len=0) */
+#define LP_NORMAL		1		/* used (should always have lp_len>0) */
+#define LP_REDIRECT		2		/* HOT redirect (should have lp_len=0) */
+#define LP_DEAD			3		/* dead, may or may not have storage */
 
 /*
- * Item offsets, lengths, and flags are represented by these types when
+ * Item offsets and lengths are represented by these types when
  * they're not actually stored in an ItemIdData.
  */
 typedef uint16 ItemOffset;
 typedef uint16 ItemLength;
 
-typedef bits16 ItemIdFlags;
-
 
 /* ----------------
  *		support macros
@@ -76,22 +71,113 @@ typedef bits16 ItemIdFlags;
    ((itemId)->lp_flags)
 
 /*
+ *		ItemIdGetRedirect
+ * In a REDIRECT pointer, lp_off holds the link to the next item pointer
+ */
+#define ItemIdGetRedirect(itemId) \
+   ((itemId)->lp_off)
+
+/*
  * ItemIdIsValid
- *		True iff disk item identifier is valid.
+ *		True iff item identifier is valid.
+ *		This is a pretty weak test, probably useful only in Asserts.
  */
 #define ItemIdIsValid(itemId)	PointerIsValid(itemId)
 
 /*
  * ItemIdIsUsed
- *		True iff disk item identifier is in use.
- *
- * Note:
- *		Assumes disk item identifier is valid.
+ *		True iff item identifier is in use.
  */
 #define ItemIdIsUsed(itemId) \
+	((itemId)->lp_flags != LP_UNUSED)
+
+/*
+ * ItemIdIsNormal
+ *		True iff item identifier is in state NORMAL.
+ */
+#define ItemIdIsNormal(itemId) \
+	((itemId)->lp_flags == LP_NORMAL)
+
+/*
+ * ItemIdIsRedirected
+ *		True iff item identifier is in state REDIRECT.
+ */
+#define ItemIdIsRedirected(itemId) \
+	((itemId)->lp_flags == LP_REDIRECT)
+
+/*
+ * ItemIdIsDead
+ *		True iff item identifier is in state DEAD.
+ */
+#define ItemIdIsDead(itemId) \
+	((itemId)->lp_flags == LP_DEAD)
+
+/*
+ * ItemIdHasStorage
+ *		True iff item identifier has associated storage.
+ */
+#define ItemIdHasStorage(itemId) \
+	((itemId)->lp_len != 0)
+
+/*
+ * ItemIdSetUnused
+ *		Set the item identifier to be UNUSED, with no storage.
+ *		Beware of multiple evaluations of itemId!
+ */
+#define ItemIdSetUnused(itemId) \
+( \
+	(itemId)->lp_flags = LP_UNUSED, \
+	(itemId)->lp_off = 0, \
+	(itemId)->lp_len = 0 \
+)
+
+/*
+ * ItemIdSetNormal
+ *		Set the item identifier to be NORMAL, with the specified storage.
+ *		Beware of multiple evaluations of itemId!
+ */
+#define ItemIdSetNormal(itemId, off, len) \
+( \
+	(itemId)->lp_flags = LP_NORMAL, \
+	(itemId)->lp_off = (off), \
+	(itemId)->lp_len = (len) \
+)
+
+/*
+ * ItemIdSetRedirect
+ *		Set the item identifier to be REDIRECT, with the specified link.
+ *		Beware of multiple evaluations of itemId!
+ */
+#define ItemIdSetRedirect(itemId, link) \
+( \
+	(itemId)->lp_flags = LP_REDIRECT, \
+	(itemId)->lp_off = (link), \
+	(itemId)->lp_len = 0 \
+)
+
+/*
+ * ItemIdSetDead
+ *		Set the item identifier to be DEAD, with no storage.
+ *		Beware of multiple evaluations of itemId!
+ */
+#define ItemIdSetDead(itemId) \
+( \
+	(itemId)->lp_flags = LP_DEAD, \
+	(itemId)->lp_off = 0, \
+	(itemId)->lp_len = 0 \
+)
+
+/*
+ * ItemIdMarkDead
+ *		Set the item identifier to be DEAD, keeping its existing storage.
+ *
+ * Note: in indexes, this is used as if it were a hint-bit mechanism;
+ * we trust that multiple processors can do this in parallel and get
+ * the same result.
+ */
+#define ItemIdMarkDead(itemId) \
 ( \
-	AssertMacro(ItemIdIsValid(itemId)), \
-	(bool) (((itemId)->lp_flags & LP_USED) != 0) \
+	(itemId)->lp_flags = LP_DEAD \
 )
 
 #endif   /* ITEMID_H */