Subject: [PATCH v18 03/18] tableam: Add insert, delete, update, lock_tuple.

From: Andres Freund <[email-masked]>
Date: Thu, 7 Mar 2019 16:23:34 -0800

Author:
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:
---
 src/backend/access/heap/heapam.c              |  88 ++---
 src/backend/access/heap/heapam_handler.c      | 353 ++++++++++++++++++
 src/backend/access/heap/heapam_visibility.c   |  23 +-
 src/backend/access/heap/tuptoaster.c          |   2 +-
 src/backend/access/table/tableam.c            | 101 +++++
 src/backend/commands/copy.c                   |   3 +-
 src/backend/commands/createas.c               |   3 -
 src/backend/commands/trigger.c                | 102 +++--
 src/backend/executor/execIndexing.c           |   4 +-
 src/backend/executor/execMain.c               | 279 +-------------
 src/backend/executor/execReplication.c        | 106 ++----
 src/backend/executor/nodeLockRows.c           |  73 ++--
 src/backend/executor/nodeModifyTable.c        | 324 +++++++++-------
 src/backend/executor/nodeTidscan.c            |   2 +-
 src/include/access/heapam.h                   |  45 +--
 src/include/access/tableam.h                  | 158 ++++++++
 src/include/executor/executor.h               |  12 +-
 src/include/nodes/lockoptions.h               |   5 +
 src/include/utils/snapshot.h                  |   1 +
 .../expected/partition-key-update-1.out       |   2 +-
 20 files changed, 1027 insertions(+), 659 deletions(-)

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index d6e32d6ce21..a2bb1701e40 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -1386,13 +1386,12 @@ heap_getnextslot(TableScanDesc sscan, ScanDirection direction, TupleTableSlot *s
  */
 bool
 heap_fetch(Relation relation,
+		   ItemPointer tid,
 		   Snapshot snapshot,
 		   HeapTuple tuple,
 		   Buffer *userbuf,
-		   bool keep_buf,
 		   Relation stats_relation)
 {
-	ItemPointer tid = &(tuple->t_self);
 	ItemId		lp;
 	Buffer		buffer;
 	Page		page;
@@ -1419,13 +1418,8 @@ heap_fetch(Relation relation,
 	if (offnum < FirstOffsetNumber || offnum > PageGetMaxOffsetNumber(page))
 	{
 		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
-		if (keep_buf)
-			*userbuf = buffer;
-		else
-		{
-			ReleaseBuffer(buffer);
-			*userbuf = InvalidBuffer;
-		}
+		ReleaseBuffer(buffer);
+		*userbuf = InvalidBuffer;
 		tuple->t_data = NULL;
 		return false;
 	}
@@ -1441,20 +1435,16 @@ heap_fetch(Relation relation,
 	if (!ItemIdIsNormal(lp))
 	{
 		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
-		if (keep_buf)
-			*userbuf = buffer;
-		else
-		{
-			ReleaseBuffer(buffer);
-			*userbuf = InvalidBuffer;
-		}
+		ReleaseBuffer(buffer);
+		*userbuf = InvalidBuffer;
 		tuple->t_data = NULL;
 		return false;
 	}
 
 	/*
-	 * fill in *tuple fields
+	 * fill in tuple fields and place it in stuple
 	 */
+	ItemPointerCopy(tid, &(tuple->t_self));
 	tuple->t_data = (HeapTupleHeader) PageGetItem(page, lp);
 	tuple->t_len = ItemIdGetLength(lp);
 	tuple->t_tableOid = RelationGetRelid(relation);
@@ -1486,14 +1476,9 @@ heap_fetch(Relation relation,
 		return true;
 	}
 
-	/* Tuple failed time qual, but maybe caller wants to see it anyway. */
-	if (keep_buf)
-		*userbuf = buffer;
-	else
-	{
-		ReleaseBuffer(buffer);
-		*userbuf = InvalidBuffer;
-	}
+	/* Tuple failed time qual */
+	ReleaseBuffer(buffer);
+	*userbuf = InvalidBuffer;
 
 	return false;
 }
@@ -2703,6 +2688,7 @@ l1:
 	{
 		Assert(result == HeapTupleSelfUpdated ||
 			   result == HeapTupleUpdated ||
+			   result == HeapTupleDeleted ||
 			   result == HeapTupleBeingUpdated);
 		Assert(!(tp.t_data->t_infomask & HEAP_XMAX_INVALID));
 		hufd->ctid = tp.t_data->t_ctid;
@@ -2716,6 +2702,8 @@ l1:
 			UnlockTupleTuplock(relation, &(tp.t_self), LockTupleExclusive);
 		if (vmbuffer != InvalidBuffer)
 			ReleaseBuffer(vmbuffer);
+		if (result == HeapTupleUpdated && ItemPointerEquals(tid, &hufd->ctid))
+			result = HeapTupleDeleted;
 		return result;
 	}
 
@@ -2932,6 +2920,10 @@ simple_heap_delete(Relation relation, ItemPointer tid)
 			elog(ERROR, "tuple concurrently updated");
 			break;
 
+		case HeapTupleDeleted:
+			elog(ERROR, "tuple concurrently deleted");
+			break;
+
 		default:
 			elog(ERROR, "unrecognized heap_delete status: %u", result);
 			break;
@@ -3336,6 +3328,7 @@ l2:
 	{
 		Assert(result == HeapTupleSelfUpdated ||
 			   result == HeapTupleUpdated ||
+			   result == HeapTupleDeleted ||
 			   result == HeapTupleBeingUpdated);
 		Assert(!(oldtup.t_data->t_infomask & HEAP_XMAX_INVALID));
 		hufd->ctid = oldtup.t_data->t_ctid;
@@ -3354,6 +3347,8 @@ l2:
 		bms_free(id_attrs);
 		bms_free(modified_attrs);
 		bms_free(interesting_attrs);
+		if (result == HeapTupleUpdated && ItemPointerEquals(otid, &hufd->ctid))
+			result = HeapTupleDeleted;
 		return result;
 	}
 
@@ -3971,6 +3966,10 @@ simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup)
 			elog(ERROR, "tuple concurrently updated");
 			break;
 
+		case HeapTupleDeleted:
+			elog(ERROR, "tuple concurrently deleted");
+			break;
+
 		default:
 			elog(ERROR, "unrecognized heap_update status: %u", result);
 			break;
@@ -4005,7 +4004,7 @@ get_mxact_status_for_lock(LockTupleMode mode, bool is_update)
  *
  * Input parameters:
  *	relation: relation containing tuple (caller must hold suitable lock)
- *	tuple->t_self: TID of tuple to lock (rest of struct need not be valid)
+ *	tid: TID of tuple to lock
  *	cid: current command ID (used for visibility test, and stored into
  *		tuple's cmax if lock is successful)
  *	mode: indicates if shared or exclusive tuple lock is desired
@@ -4023,6 +4022,7 @@ get_mxact_status_for_lock(LockTupleMode mode, bool is_update)
  *	HeapTupleInvisible: lock failed because tuple was never visible to us
  *	HeapTupleSelfUpdated: lock failed because tuple updated by self
  *	HeapTupleUpdated: lock failed because tuple updated by other xact
+ *	HeapTupleDeleted: lock failed because tuple deleted by other xact
  *	HeapTupleWouldBlock: lock couldn't be acquired and wait_policy is skip
  *
  * In the failure cases other than HeapTupleInvisible, the routine fills
@@ -4035,13 +4035,12 @@ get_mxact_status_for_lock(LockTupleMode mode, bool is_update)
  * See README.tuplock for a thorough explanation of this mechanism.
  */
 HTSU_Result
-heap_lock_tuple(Relation relation, HeapTuple tuple,
+heap_lock_tuple(Relation relation, ItemPointer tid,
 				CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
 				bool follow_updates,
-				Buffer *buffer, HeapUpdateFailureData *hufd)
+				HeapTuple tuple, Buffer *buffer, HeapUpdateFailureData *hufd)
 {
 	HTSU_Result result;
-	ItemPointer tid = &(tuple->t_self);
 	ItemId		lp;
 	Page		page;
 	Buffer		vmbuffer = InvalidBuffer;
@@ -4076,6 +4075,7 @@ heap_lock_tuple(Relation relation, HeapTuple tuple,
 	tuple->t_data = (HeapTupleHeader) PageGetItem(page, lp);
 	tuple->t_len = ItemIdGetLength(lp);
 	tuple->t_tableOid = RelationGetRelid(relation);
+	tuple->t_self = *tid;
 
 l3:
 	result = HeapTupleSatisfiesUpdate(tuple, cid, *buffer);
@@ -4091,7 +4091,7 @@ l3:
 		result = HeapTupleInvisible;
 		goto out_locked;
 	}
-	else if (result == HeapTupleBeingUpdated || result == HeapTupleUpdated)
+	else if (result == HeapTupleBeingUpdated || result == HeapTupleUpdated || result == HeapTupleDeleted)
 	{
 		TransactionId xwait;
 		uint16		infomask;
@@ -4371,7 +4371,7 @@ l3:
 		 * or we must wait for the locking transaction or multixact; so below
 		 * we ensure that we grab buffer lock after the sleep.
 		 */
-		if (require_sleep && result == HeapTupleUpdated)
+		if (require_sleep && (result == HeapTupleUpdated || result == HeapTupleDeleted))
 		{
 			LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
 			goto failed;
@@ -4531,6 +4531,8 @@ l3:
 			HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_data->t_infomask) ||
 			HeapTupleHeaderIsOnlyLocked(tuple->t_data))
 			result = HeapTupleMayBeUpdated;
+		else if (ItemPointerEquals(&tuple->t_self, &tuple->t_data->t_ctid))
+			result = HeapTupleDeleted;
 		else
 			result = HeapTupleUpdated;
 	}
@@ -4539,7 +4541,7 @@ failed:
 	if (result != HeapTupleMayBeUpdated)
 	{
 		Assert(result == HeapTupleSelfUpdated || result == HeapTupleUpdated ||
-			   result == HeapTupleWouldBlock);
+			   result == HeapTupleWouldBlock || result == HeapTupleDeleted);
 		Assert(!(tuple->t_data->t_infomask & HEAP_XMAX_INVALID));
 		hufd->ctid = tuple->t_data->t_ctid;
 		hufd->xmax = HeapTupleHeaderGetUpdateXid(tuple->t_data);
@@ -5143,9 +5145,8 @@ heap_lock_updated_tuple_rec(Relation rel, ItemPointer tid, TransactionId xid,
 		new_infomask = 0;
 		new_xmax = InvalidTransactionId;
 		block = ItemPointerGetBlockNumber(&tupid);
-		ItemPointerCopy(&tupid, &(mytup.t_self));
 
-		if (!heap_fetch(rel, SnapshotAny, &mytup, &buf, false, NULL))
+		if (!heap_fetch(rel, &tupid, SnapshotAny, &mytup, &buf, NULL))
 		{
 			/*
 			 * if we fail to find the updated version of the tuple, it's
@@ -5428,6 +5429,10 @@ next:
 	result = HeapTupleMayBeUpdated;
 
 out_locked:
+
+	if (result == HeapTupleUpdated && ItemPointerEquals(&mytup.t_self, &mytup.t_data->t_ctid))
+		result = HeapTupleDeleted;
+
 	UnlockReleaseBuffer(buf);
 
 out_unlocked:
@@ -5505,7 +5510,7 @@ heap_lock_updated_tuple(Relation rel, HeapTuple tuple, ItemPointer ctid,
  * An explicit confirmation WAL record also makes logical decoding simpler.
  */
 void
-heap_finish_speculative(Relation relation, HeapTuple tuple)
+heap_finish_speculative(Relation relation, ItemPointer tid)
 {
 	Buffer		buffer;
 	Page		page;
@@ -5513,11 +5518,11 @@ heap_finish_speculative(Relation relation, HeapTuple tuple)
 	ItemId		lp = NULL;
 	HeapTupleHeader htup;
 
-	buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(&(tuple->t_self)));
+	buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
 	LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
 	page = (Page) BufferGetPage(buffer);
 
-	offnum = ItemPointerGetOffsetNumber(&(tuple->t_self));
+	offnum = ItemPointerGetOffsetNumber(tid);
 	if (PageGetMaxOffsetNumber(page) >= offnum)
 		lp = PageGetItemId(page, offnum);
 
@@ -5533,7 +5538,7 @@ heap_finish_speculative(Relation relation, HeapTuple tuple)
 	/* NO EREPORT(ERROR) from here till changes are logged */
 	START_CRIT_SECTION();
 
-	Assert(HeapTupleHeaderIsSpeculative(tuple->t_data));
+	Assert(HeapTupleHeaderIsSpeculative(htup));
 
 	MarkBufferDirty(buffer);
 
@@ -5541,7 +5546,7 @@ heap_finish_speculative(Relation relation, HeapTuple tuple)
 	 * Replace the speculative insertion token with a real t_ctid, pointing to
 	 * itself like it does on regular tuples.
 	 */
-	htup->t_ctid = tuple->t_self;
+	htup->t_ctid = *tid;
 
 	/* XLOG stuff */
 	if (RelationNeedsWAL(relation))
@@ -5549,7 +5554,7 @@ heap_finish_speculative(Relation relation, HeapTuple tuple)
 		xl_heap_confirm xlrec;
 		XLogRecPtr	recptr;
 
-		xlrec.offnum = ItemPointerGetOffsetNumber(&tuple->t_self);
+		xlrec.offnum = ItemPointerGetOffsetNumber(tid);
 
 		XLogBeginInsert();
 
@@ -5596,10 +5601,9 @@ heap_finish_speculative(Relation relation, HeapTuple tuple)
  * confirmation records.
  */
 void
-heap_abort_speculative(Relation relation, HeapTuple tuple)
+heap_abort_speculative(Relation relation, ItemPointer tid)
 {
 	TransactionId xid = GetCurrentTransactionId();
-	ItemPointer tid = &(tuple->t_self);
 	ItemId		lp;
 	HeapTupleData tp;
 	Page		page;
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 6a26fcef94c..3285197c558 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -21,7 +21,9 @@
 
 #include "access/heapam.h"
 #include "access/tableam.h"
+#include "access/xact.h"
 #include "storage/bufmgr.h"
+#include "storage/lmgr.h"
 #include "utils/builtins.h"

@@ -169,6 +171,350 @@ heapam_tuple_satisfies_snapshot(Relation rel, TupleTableSlot *slot,
 }

+/* ----------------------------------------------------------------------------
+ *  Functions for manipulations of physical tuples for heap AM.
+ * ----------------------------------------------------------------------------
+ */
+
+/*
+ * Insert a heap tuple from a slot, which may contain an OID and speculative
+ * insertion token.
+ */
+static void
+heapam_heap_insert(Relation relation, TupleTableSlot *slot, CommandId cid,
+				   int options, BulkInsertState bistate)
+{
+	bool		shouldFree = true;
+	HeapTuple	tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
+
+	/* Update the tuple with table oid */
+	slot->tts_tableOid = RelationGetRelid(relation);
+	if (slot->tts_tableOid != InvalidOid)
+		tuple->t_tableOid = slot->tts_tableOid;
+
+	/* Perform the insertion, and copy the resulting ItemPointer */
+	heap_insert(relation, tuple, cid, options, bistate);
+	ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
+
+	if (shouldFree)
+		pfree(tuple);
+}
+
+static void
+heapam_heap_insert_speculative(Relation relation, TupleTableSlot *slot, CommandId cid,
+							   int options, BulkInsertState bistate, uint32 specToken)
+{
+	bool		shouldFree = true;
+	HeapTuple	tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
+
+	/* Update the tuple with table oid */
+	slot->tts_tableOid = RelationGetRelid(relation);
+	if (slot->tts_tableOid != InvalidOid)
+		tuple->t_tableOid = slot->tts_tableOid;
+
+	HeapTupleHeaderSetSpeculativeToken(tuple->t_data, specToken);
+
+	/* Perform the insertion, and copy the resulting ItemPointer */
+	heap_insert(relation, tuple, cid, options, bistate);
+	ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
+
+	if (shouldFree)
+		pfree(tuple);
+}
+
+static void
+heapam_heap_complete_speculative(Relation relation, TupleTableSlot *slot, uint32 spekToken,
+								 bool succeeded)
+{
+	bool		shouldFree = true;
+	HeapTuple	tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
+
+	/* adjust the tuple's state accordingly */
+	if (!succeeded)
+		heap_finish_speculative(relation, &slot->tts_tid);
+	else
+		heap_abort_speculative(relation, &slot->tts_tid);
+
+	if (shouldFree)
+		pfree(tuple);
+}
+
+static HTSU_Result
+heapam_heap_delete(Relation relation, ItemPointer tid, CommandId cid,
+				   Snapshot snapshot, Snapshot crosscheck, bool wait,
+				   HeapUpdateFailureData *hufd, bool changingPart)
+{
+	/*
+	 * Currently Deleting of index tuples are handled at vacuum, in case if
+	 * the storage itself is cleaning the dead tuples by itself, it is the
+	 * time to call the index tuple deletion also.
+	 */
+	return heap_delete(relation, tid, cid, crosscheck, wait, hufd, changingPart);
+}
+
+
+static HTSU_Result
+heapam_heap_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
+				   CommandId cid, Snapshot snapshot, Snapshot crosscheck,
+				   bool wait, HeapUpdateFailureData *hufd,
+				   LockTupleMode *lockmode, bool *update_indexes)
+{
+	bool		shouldFree = true;
+	HeapTuple	tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
+	HTSU_Result result;
+
+	/* Update the tuple with table oid */
+	if (slot->tts_tableOid != InvalidOid)
+		tuple->t_tableOid = slot->tts_tableOid;
+
+	result = heap_update(relation, otid, tuple, cid, crosscheck, wait,
+						 hufd, lockmode);
+	ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
+
+	slot->tts_tableOid = RelationGetRelid(relation);
+
+	/*
+	 * Decide whether new index entries are needed for the tuple
+	 *
+	 * Note: heap_update returns the tid (location) of the new tuple in the
+	 * t_self field.
+	 *
+	 * If it's a HOT update, we mustn't insert new index entries.
+	 */
+	*update_indexes = result == HeapTupleMayBeUpdated &&
+		!HeapTupleIsHeapOnly(tuple);
+
+	if (shouldFree)
+		pfree(tuple);
+
+	return result;
+}
+
+/*
+ * Locks tuple and fetches its newest version and TID.
+ *
+ *	relation - table containing tuple
+ *	tid - TID of tuple to lock
+ *	snapshot - snapshot indentifying required version (used for assert check only)
+ *	slot - tuple to be returned
+ *	cid - current command ID (used for visibility test, and stored into
+ *		  tuple's cmax if lock is successful)
+ *	mode - indicates if shared or exclusive tuple lock is desired
+ *	wait_policy - what to do if tuple lock is not available
+ *	flags – indicating how do we handle updated tuples
+ *	*hufd - filled in failure cases
+ *
+ * Function result may be:
+ *	HeapTupleMayBeUpdated: lock was successfully acquired
+ *	HeapTupleInvisible: lock failed because tuple was never visible to us
+ *	HeapTupleSelfUpdated: lock failed because tuple updated by self
+ *	HeapTupleUpdated: lock failed because tuple updated by other xact
+ *	HeapTupleDeleted: lock failed because tuple deleted by other xact
+ *	HeapTupleWouldBlock: lock couldn't be acquired and wait_policy is skip
+ *
+ * In the failure cases other than HeapTupleInvisible, the routine fills
+ * *hufd with the tuple's t_ctid, t_xmax (resolving a possible MultiXact,
+ * if necessary), and t_cmax (the last only for HeapTupleSelfUpdated,
+ * since we cannot obtain cmax from a combocid generated by another
+ * transaction).
+ * See comments for struct HeapUpdateFailureData for additional info.
+ */
+static HTSU_Result
+heapam_lock_tuple(Relation relation, ItemPointer tid, Snapshot snapshot,
+				  TupleTableSlot *slot, CommandId cid, LockTupleMode mode,
+				  LockWaitPolicy wait_policy, uint8 flags,
+				  HeapUpdateFailureData *hufd)
+{
+	BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
+	HTSU_Result result;
+	Buffer		buffer;
+	HeapTuple	tuple = &bslot->base.tupdata;
+
+	hufd->traversed = false;
+
+	Assert(TTS_IS_BUFFERTUPLE(slot));
+
+retry:
+	result = heap_lock_tuple(relation, tid, cid, mode, wait_policy,
+							 (flags & TUPLE_LOCK_FLAG_LOCK_UPDATE_IN_PROGRESS) ? true : false,
+							 tuple, &buffer, hufd);
+
+	if (result == HeapTupleUpdated &&
+		(flags & TUPLE_LOCK_FLAG_FIND_LAST_VERSION))
+	{
+		ReleaseBuffer(buffer);
+		/* Should not encounter speculative tuple on recheck */
+		Assert(!HeapTupleHeaderIsSpeculative(tuple->t_data));
+
+		if (!ItemPointerEquals(&hufd->ctid, &tuple->t_self))
+		{
+			SnapshotData SnapshotDirty;
+			TransactionId priorXmax;
+
+			/* it was updated, so look at the updated version */
+			*tid = hufd->ctid;
+			/* updated row should have xmin matching this xmax */
+			priorXmax = hufd->xmax;
+
+			/*
+			 * fetch target tuple
+			 *
+			 * Loop here to deal with updated or busy tuples
+			 */
+			InitDirtySnapshot(SnapshotDirty);
+			for (;;)
+			{
+				if (ItemPointerIndicatesMovedPartitions(tid))
+					ereport(ERROR,
+							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+							 errmsg("tuple to be locked was already moved to another partition due to concurrent update")));
+
+
+				if (heap_fetch(relation, tid, &SnapshotDirty, tuple, &buffer, NULL))
+				{
+					/*
+					 * If xmin isn't what we're expecting, the slot must have
+					 * been recycled and reused for an unrelated tuple.  This
+					 * implies that the latest version of the row was deleted,
+					 * so we need do nothing.  (Should be safe to examine xmin
+					 * without getting buffer's content lock.  We assume
+					 * reading a TransactionId to be atomic, and Xmin never
+					 * changes in an existing tuple, except to invalid or
+					 * frozen, and neither of those can match priorXmax.)
+					 */
+					if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple->t_data),
+											 priorXmax))
+					{
+						ReleaseBuffer(buffer);
+						return HeapTupleDeleted;
+					}
+
+					/* otherwise xmin should not be dirty... */
+					if (TransactionIdIsValid(SnapshotDirty.xmin))
+						elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
+
+					/*
+					 * If tuple is being updated by other transaction then we
+					 * have to wait for its commit/abort, or die trying.
+					 */
+					if (TransactionIdIsValid(SnapshotDirty.xmax))
+					{
+						ReleaseBuffer(buffer);
+						switch (wait_policy)
+						{
+							case LockWaitBlock:
+								XactLockTableWait(SnapshotDirty.xmax,
+												  relation, &tuple->t_self,
+												  XLTW_FetchUpdated);
+								break;
+							case LockWaitSkip:
+								if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
+									return result;	/* skip instead of waiting */
+								break;
+							case LockWaitError:
+								if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
+									ereport(ERROR,
+											(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
+											 errmsg("could not obtain lock on row in relation \"%s\"",
+													RelationGetRelationName(relation))));
+								break;
+						}
+						continue;	/* loop back to repeat heap_fetch */
+					}
+
+					/*
+					 * If tuple was inserted by our own transaction, we have
+					 * to check cmin against es_output_cid: cmin >= current
+					 * CID means our command cannot see the tuple, so we
+					 * should ignore it. Otherwise heap_lock_tuple() will
+					 * throw an error, and so would any later attempt to
+					 * update or delete the tuple.  (We need not check cmax
+					 * because HeapTupleSatisfiesDirty will consider a tuple
+					 * deleted by our transaction dead, regardless of cmax.)
+					 * We just checked that priorXmax == xmin, so we can test
+					 * that variable instead of doing HeapTupleHeaderGetXmin
+					 * again.
+					 */
+					if (TransactionIdIsCurrentTransactionId(priorXmax) &&
+						HeapTupleHeaderGetCmin(tuple->t_data) >= cid)
+					{
+						ReleaseBuffer(buffer);
+						return result;
+					}
+
+					hufd->traversed = true;
+					*tid = tuple->t_data->t_ctid;
+					ReleaseBuffer(buffer);
+					goto retry;
+				}
+
+				/*
+				 * If the referenced slot was actually empty, the latest
+				 * version of the row must have been deleted, so we need do
+				 * nothing.
+				 */
+				if (tuple->t_data == NULL)
+				{
+					return HeapTupleDeleted;
+				}
+
+				/*
+				 * As above, if xmin isn't what we're expecting, do nothing.
+				 */
+				if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple->t_data),
+										 priorXmax))
+				{
+					if (BufferIsValid(buffer))
+						ReleaseBuffer(buffer);
+					return HeapTupleDeleted;
+				}
+
+				/*
+				 * If we get here, the tuple was found but failed
+				 * SnapshotDirty. Assuming the xmin is either a committed xact
+				 * or our own xact (as it certainly should be if we're trying
+				 * to modify the tuple), this must mean that the row was
+				 * updated or deleted by either a committed xact or our own
+				 * xact.  If it was deleted, we can ignore it; if it was
+				 * updated then chain up to the next version and repeat the
+				 * whole process.
+				 *
+				 * As above, it should be safe to examine xmax and t_ctid
+				 * without the buffer content lock, because they can't be
+				 * changing.
+				 */
+				if (ItemPointerEquals(&tuple->t_self, &tuple->t_data->t_ctid))
+				{
+					/* deleted, so forget about it */
+					if (BufferIsValid(buffer))
+						ReleaseBuffer(buffer);
+					return HeapTupleDeleted;
+				}
+
+				/* updated, so look at the updated row */
+				*tid = tuple->t_data->t_ctid;
+				/* updated row should have xmin matching this xmax */
+				priorXmax = HeapTupleHeaderGetUpdateXid(tuple->t_data);
+				if (BufferIsValid(buffer))
+					ReleaseBuffer(buffer);
+				/* loop back to fetch next in chain */
+			}
+		}
+		else
+		{
+			/* tuple was deleted, so give up */
+			return HeapTupleDeleted;
+		}
+	}
+
+	slot->tts_tableOid = RelationGetRelid(relation);
+	/* store in slot, transferring existing pin */
+	ExecStorePinnedBufferHeapTuple(tuple, slot, buffer);
+
+	return result;
+}
+
+
 /* ------------------------------------------------------------------------
  * Definition of the heap table access method.
  * ------------------------------------------------------------------------
@@ -193,6 +539,13 @@ static const TableAmRoutine heapam_methods = {
 	.index_fetch_end = heapam_index_fetch_end,
 	.index_fetch_tuple = heapam_index_fetch_tuple,
 
+	.tuple_insert = heapam_heap_insert,
+	.tuple_insert_speculative = heapam_heap_insert_speculative,
+	.tuple_complete_speculative = heapam_heap_complete_speculative,
+	.tuple_delete = heapam_heap_delete,
+	.tuple_update = heapam_heap_update,
+	.tuple_lock = heapam_lock_tuple,
+
 	.tuple_satisfies_snapshot = heapam_tuple_satisfies_snapshot,
 };
 
diff --git a/src/backend/access/heap/heapam_visibility.c b/src/backend/access/heap/heapam_visibility.c
index 6cb38f80c68..5e8fdacb951 100644
--- a/src/backend/access/heap/heapam_visibility.c
+++ b/src/backend/access/heap/heapam_visibility.c
@@ -112,6 +112,9 @@ static inline void
 SetHintBits(HeapTupleHeader tuple, Buffer buffer,
 			uint16 infomask, TransactionId xid)
 {
+	if (!BufferIsValid(buffer))
+		return;
+
 	if (TransactionIdIsValid(xid))
 	{
 		/* NB: xid must be known committed here! */
@@ -606,7 +609,11 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
 	{
 		if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
 			return HeapTupleMayBeUpdated;
-		return HeapTupleUpdated;	/* updated by other */
+		/* updated by other */
+		if (ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
+			return HeapTupleDeleted;
+		else
+			return HeapTupleUpdated;
 	}
 
 	if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
@@ -647,7 +654,12 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
 			return HeapTupleBeingUpdated;
 
 		if (TransactionIdDidCommit(xmax))
-			return HeapTupleUpdated;
+		{
+			if (ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
+				return HeapTupleDeleted;
+			else
+				return HeapTupleUpdated;
+		}
 
 		/*
 		 * By here, the update in the Xmax is either aborted or crashed, but
@@ -703,7 +715,12 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
 
 	SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
 				HeapTupleHeaderGetRawXmax(tuple));
-	return HeapTupleUpdated;	/* updated by other */
+
+	/* updated by other */
+	if (ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
+		return HeapTupleDeleted;
+	else
+		return HeapTupleUpdated;
 }
 
 /*
diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c
index cd921a46005..a40cfcf1954 100644
--- a/src/backend/access/heap/tuptoaster.c
+++ b/src/backend/access/heap/tuptoaster.c
@@ -1763,7 +1763,7 @@ toast_delete_datum(Relation rel, Datum value, bool is_speculative)
 		 * Have a chunk, delete it
 		 */
 		if (is_speculative)
-			heap_abort_speculative(toastrel, toasttup);
+			heap_abort_speculative(toastrel, &toasttup->t_self);
 		else
 			simple_heap_delete(toastrel, &toasttup->t_self);
 	}
diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c
index 628d930c130..9a01f74d8fe 100644
--- a/src/backend/access/table/tableam.c
+++ b/src/backend/access/table/tableam.c
@@ -176,6 +176,107 @@ table_beginscan_parallel(Relation relation, ParallelTableScanDesc parallel_scan)
 }

+/* ----------------------------------------------------------------------------
+ * Functions to make modifications a bit simpler.
+ * ----------------------------------------------------------------------------
+ */
+
+/*
+ *	simple_table_update - replace a tuple
+ *
+ * This routine may be used to update a tuple when concurrent updates of
+ * the target tuple are not expected (for example, because we have a lock
+ * on the relation associated with the tuple).  Any failure is reported
+ * via ereport().
+ */
+void
+simple_table_update(Relation rel, ItemPointer otid,
+					TupleTableSlot *slot,
+					Snapshot snapshot,
+					bool *update_indexes)
+{
+	HTSU_Result result;
+	HeapUpdateFailureData hufd;
+	LockTupleMode lockmode;
+
+	result = table_update(rel, otid, slot,
+						  GetCurrentCommandId(true),
+						  snapshot, InvalidSnapshot,
+						  true /* wait for commit */ ,
+						  &hufd, &lockmode, update_indexes);
+
+	switch (result)
+	{
+		case HeapTupleSelfUpdated:
+			/* Tuple was already updated in current command? */
+			elog(ERROR, "tuple already updated by self");
+			break;
+
+		case HeapTupleMayBeUpdated:
+			/* done successfully */
+			break;
+
+		case HeapTupleUpdated:
+			elog(ERROR, "tuple concurrently updated");
+			break;
+
+		case HeapTupleDeleted:
+			elog(ERROR, "tuple concurrently deleted");
+			break;
+
+		default:
+			elog(ERROR, "unrecognized heap_update status: %u", result);
+			break;
+	}
+
+}
+
+/*
+ *	simple_table_delete - delete a tuple
+ *
+ * This routine may be used to delete a tuple when concurrent updates of
+ * the target tuple are not expected (for example, because we have a lock
+ * on the relation associated with the tuple).  Any failure is reported
+ * via ereport().
+ */
+void
+simple_table_delete(Relation rel, ItemPointer tid, Snapshot snapshot)
+{
+	HTSU_Result result;
+	HeapUpdateFailureData hufd;
+
+	result = table_delete(rel, tid,
+						  GetCurrentCommandId(true),
+						  snapshot, InvalidSnapshot,
+						  true /* wait for commit */ ,
+						  &hufd, false /* changingPart */ );
+
+	switch (result)
+	{
+		case HeapTupleSelfUpdated:
+			/* Tuple was already updated in current command? */
+			elog(ERROR, "tuple already updated by self");
+			break;
+
+		case HeapTupleMayBeUpdated:
+			/* done successfully */
+			break;
+
+		case HeapTupleUpdated:
+			elog(ERROR, "tuple concurrently updated");
+			break;
+
+		case HeapTupleDeleted:
+			elog(ERROR, "tuple concurrently deleted");
+			break;
+
+		default:
+			elog(ERROR, "unrecognized heap_delete status: %u", result);
+			break;
+	}
+}
+
+
 /* ----------------------------------------------------------------------------
  * Helper functions to implement parallel scans for block oriented AMs.
  * ----------------------------------------------------------------------------
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index f2731b40757..aba93262383 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -3003,7 +3003,6 @@ CopyFrom(CopyState cstate)
 					/* And create index entries for it */
 					if (resultRelInfo->ri_NumIndices > 0)
 						recheckIndexes = ExecInsertIndexTuples(slot,
-															   &(tuple->t_self),
 															   estate,
 															   false,
 															   NULL,
@@ -3147,7 +3146,7 @@ CopyFromInsertBatch(CopyState cstate, EState *estate, CommandId mycid,
 			cstate->cur_lineno = firstBufferedLineNo + i;
 			ExecStoreHeapTuple(bufferedTuples[i], myslot, false);
 			recheckIndexes =
-				ExecInsertIndexTuples(myslot, &(bufferedTuples[i]->t_self),
+				ExecInsertIndexTuples(myslot,
 									  estate, false, NULL, NIL);
 			ExecARInsertTriggers(estate, resultRelInfo,
 								 myslot,
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 36e3d44aad6..0ac295cea3f 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -588,9 +588,6 @@ intorel_receive(TupleTableSlot *slot, DestReceiver *self)
 
 	/* We know this is a newly created relation, so there are no indexes */
 
-	/* Free the copied tuple. */
-	heap_freetuple(tuple);
-
 	return true;
 }
 
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 71098896947..5cc15bcfef0 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -15,6 +15,7 @@
 
 #include "access/genam.h"
 #include "access/heapam.h"
+#include "access/tableam.h"
 #include "access/sysattr.h"
 #include "access/htup_details.h"
 #include "access/xact.h"
@@ -3285,14 +3286,6 @@ GetTupleForTrigger(EState *estate,
 				   TupleTableSlot **newSlot)
 {
 	Relation	relation = relinfo->ri_RelationDesc;
-	HeapTuple	tuple;
-	Buffer		buffer;
-	BufferHeapTupleTableSlot *boldslot;
-
-	Assert(TTS_IS_BUFFERTUPLE(oldslot));
-	ExecClearTuple(oldslot);
-	boldslot = (BufferHeapTupleTableSlot *) oldslot;
-	tuple = &boldslot->base.tupdata;
 
 	if (newSlot != NULL)
 	{
@@ -3307,12 +3300,12 @@ GetTupleForTrigger(EState *estate,
 		/*
 		 * lock tuple for update
 		 */
-ltrmark:;
-		tuple->t_self = *tid;
-		test = heap_lock_tuple(relation, tuple,
-							   estate->es_output_cid,
-							   lockmode, LockWaitBlock,
-							   false, &buffer, &hufd);
+		test = table_lock_tuple(relation, tid, estate->es_snapshot, oldslot,
+								estate->es_output_cid,
+								lockmode, LockWaitBlock,
+								IsolationUsesXactSnapshot() ? 0 : TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
+								&hufd);
+
 		switch (test)
 		{
 			case HeapTupleSelfUpdated:
@@ -3332,57 +3325,50 @@ ltrmark:;
 							 errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
 
 				/* treat it as deleted; do not process */
-				ReleaseBuffer(buffer);
 				return false;
 
 			case HeapTupleMayBeUpdated:
-				ExecStorePinnedBufferHeapTuple(tuple, oldslot, buffer);
-
-				break;
-
-			case HeapTupleUpdated:
-				ReleaseBuffer(buffer);
-				if (IsolationUsesXactSnapshot())
-					ereport(ERROR,
-							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-							 errmsg("could not serialize access due to concurrent update")));
-				if (ItemPointerIndicatesMovedPartitions(&hufd.ctid))
-					ereport(ERROR,
-							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-							 errmsg("tuple to be locked was already moved to another partition due to concurrent update")));
-
-				if (!ItemPointerEquals(&hufd.ctid, &tuple->t_self))
+				if (hufd.traversed)
 				{
-					/* it was updated, so look at the updated version */
+					TupleTableSlot *testslot;
 					TupleTableSlot *epqslot;
 
+					EvalPlanQualBegin(epqstate, estate);
+
+					testslot = EvalPlanQualSlot(epqstate, relation, relinfo->ri_RangeTableIndex);
+					ExecCopySlot(testslot, oldslot);
+
 					epqslot = EvalPlanQual(estate,
 										   epqstate,
 										   relation,
 										   relinfo->ri_RangeTableIndex,
-										   lockmode,
-										   &hufd.ctid,
-										   hufd.xmax);
-					if (!TupIsNull(epqslot))
-					{
-						*tid = hufd.ctid;
+										   testslot);
 
-						*newSlot = epqslot;
+					/*
+					 * If PlanQual failed for updated tuple - we must not
+					 * process this tuple!
+					 */
+					if (TupIsNull(epqslot))
+						return false;
 
-						/*
-						 * EvalPlanQual already locked the tuple, but we
-						 * re-call heap_lock_tuple anyway as an easy way of
-						 * re-fetching the correct tuple.  Speed is hardly a
-						 * criterion in this path anyhow.
-						 */
-						goto ltrmark;
-					}
+					*newSlot = epqslot;
 				}
+				break;
 
-				/*
-				 * if tuple was deleted or PlanQual failed for updated tuple -
-				 * we must not process this tuple!
-				 */
+			case HeapTupleUpdated:
+				if (IsolationUsesXactSnapshot())
+					ereport(ERROR,
+							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+							 errmsg("could not serialize access due to concurrent update")));
+				elog(ERROR, "wrong heap_lock_tuple status: %u", test);
+				break;
+
+			case HeapTupleDeleted:
+				if (IsolationUsesXactSnapshot())
+					ereport(ERROR,
+							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+							 errmsg("could not serialize access due to concurrent update")));
+				/* tuple was deleted */
 				return false;
 
 			case HeapTupleInvisible:
@@ -3390,15 +3376,23 @@ ltrmark:;
 				break;
 
 			default:
-				ReleaseBuffer(buffer);
 				elog(ERROR, "unrecognized heap_lock_tuple status: %u", test);
 				return false;	/* keep compiler quiet */
 		}
 	}
 	else
 	{
+
 		Page		page;
 		ItemId		lp;
+		Buffer		buffer;
+		BufferHeapTupleTableSlot *boldslot;
+		HeapTuple tuple;
+
+		Assert(TTS_IS_BUFFERTUPLE(oldslot));
+		ExecClearTuple(oldslot);
+		boldslot = (BufferHeapTupleTableSlot *) oldslot;
+		tuple = &boldslot->base.tupdata;
 
 		buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
 
@@ -4286,7 +4280,7 @@ AfterTriggerExecute(EState *estate,
 				LocTriggerData.tg_trigslot = ExecGetTriggerOldSlot(estate, relInfo);
 
 				ItemPointerCopy(&(event->ate_ctid1), &(tuple1.t_self));
-				if (!heap_fetch(rel, SnapshotAny, &tuple1, &buffer, false, NULL))
+				if (!heap_fetch(rel, &(tuple1.t_self), SnapshotAny, &tuple1, &buffer, NULL))
 					elog(ERROR, "failed to fetch tuple1 for AFTER trigger");
 				ExecStorePinnedBufferHeapTuple(&tuple1,
 											   LocTriggerData.tg_trigslot,
@@ -4310,7 +4304,7 @@ AfterTriggerExecute(EState *estate,
 				LocTriggerData.tg_newslot = ExecGetTriggerNewSlot(estate, relInfo);
 
 				ItemPointerCopy(&(event->ate_ctid2), &(tuple2.t_self));
-				if (!heap_fetch(rel, SnapshotAny, &tuple2, &buffer, false, NULL))
+				if (!heap_fetch(rel, &(tuple2.t_self), SnapshotAny, &tuple2, &buffer, NULL))
 					elog(ERROR, "failed to fetch tuple2 for AFTER trigger");
 				ExecStorePinnedBufferHeapTuple(&tuple2,
 											   LocTriggerData.tg_newslot,
diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index e67dd6750c6..3b602bb8baf 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -271,12 +271,12 @@ ExecCloseIndices(ResultRelInfo *resultRelInfo)
  */
 List *
 ExecInsertIndexTuples(TupleTableSlot *slot,
-					  ItemPointer tupleid,
 					  EState *estate,
 					  bool noDupErr,
 					  bool *specConflict,
 					  List *arbiterIndexes)
 {
+	ItemPointer tupleid = &slot->tts_tid;
 	List	   *result = NIL;
 	ResultRelInfo *resultRelInfo;
 	int			i;
@@ -288,6 +288,8 @@ ExecInsertIndexTuples(TupleTableSlot *slot,
 	Datum		values[INDEX_MAX_KEYS];
 	bool		isnull[INDEX_MAX_KEYS];
 
+	Assert(ItemPointerIsValid(tupleid));
+
 	/*
 	 * Get information from the result relation info structure.
 	 */
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 5a9ffe59c47..8723e32dd58 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -2425,9 +2425,7 @@ ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
  *	epqstate - state for EvalPlanQual rechecking
  *	relation - table containing tuple
  *	rti - rangetable index of table containing tuple
- *	lockmode - requested tuple lock mode
- *	*tid - t_ctid from the outdated tuple (ie, next updated version)
- *	priorXmax - t_xmax from the outdated tuple
+ *	tuple - tuple for processing
  *
  * *tid is also an output parameter: it's modified to hold the TID of the
  * latest version of the tuple (note this may be changed even on failure)
@@ -2437,11 +2435,9 @@ ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
  */
 TupleTableSlot *
 EvalPlanQual(EState *estate, EPQState *epqstate,
-			 Relation relation, Index rti, LockTupleMode lockmode,
-			 ItemPointer tid, TransactionId priorXmax)
+			 Relation relation, Index rti, TupleTableSlot *testslot)
 {
 	TupleTableSlot *slot;
-	TupleTableSlot *testslot;
 
 	Assert(rti > 0);
 
@@ -2450,20 +2446,7 @@ EvalPlanQual(EState *estate, EPQState *epqstate,
 	 */
 	EvalPlanQualBegin(epqstate, estate);
 
-	/*
-	 * Get and lock the updated version of the row; if fail, return NULL.
-	 */
-	testslot = EvalPlanQualSlot(epqstate, relation, rti);
-	if (!EvalPlanQualFetch(estate, relation, lockmode, LockWaitBlock,
-						   tid, priorXmax,
-						   testslot))
-		return NULL;
-
-	/*
-	 * For UPDATE/DELETE we have to return tid of actual row we're executing
-	 * PQ for.
-	 */
-	*tid = testslot->tts_tid;
+	Assert(testslot == epqstate->estate->es_epqTupleSlot[rti - 1]);
 
 	/*
 	 * Fetch any non-locked source rows
@@ -2495,258 +2478,6 @@ EvalPlanQual(EState *estate, EPQState *epqstate,
 	return slot;
 }
 
-/*
- * Fetch a copy of the newest version of an outdated tuple
- *
- *	estate - executor state data
- *	relation - table containing tuple
- *	lockmode - requested tuple lock mode
- *	wait_policy - requested lock wait policy
- *	*tid - t_ctid from the outdated tuple (ie, next updated version)
- *	priorXmax - t_xmax from the outdated tuple
- *	slot - slot to store newest tuple version
- *
- * Returns true, with slot containing the newest tuple version, or false if we
- * find that there is no newest version (ie, the row was deleted not updated).
- * We also return false if the tuple is locked and the wait policy is to skip
- * such tuples.
- *
- * If successful, we have locked the newest tuple version, so caller does not
- * need to worry about it changing anymore.
- */
-bool
-EvalPlanQualFetch(EState *estate, Relation relation, LockTupleMode lockmode,
-				  LockWaitPolicy wait_policy,
-				  ItemPointer tid, TransactionId priorXmax,
-				  TupleTableSlot *slot)
-{
-	HeapTupleData tuple;
-	SnapshotData SnapshotDirty;
-
-	/*
-	 * fetch target tuple
-	 *
-	 * Loop here to deal with updated or busy tuples
-	 */
-	InitDirtySnapshot(SnapshotDirty);
-	tuple.t_self = *tid;
-	for (;;)
-	{
-		Buffer		buffer;
-
-		if (heap_fetch(relation, &SnapshotDirty, &tuple, &buffer, true, NULL))
-		{
-			HTSU_Result test;
-			HeapUpdateFailureData hufd;
-
-			/*
-			 * If xmin isn't what we're expecting, the slot must have been
-			 * recycled and reused for an unrelated tuple.  This implies that
-			 * the latest version of the row was deleted, so we need do
-			 * nothing.  (Should be safe to examine xmin without getting
-			 * buffer's content lock.  We assume reading a TransactionId to be
-			 * atomic, and Xmin never changes in an existing tuple, except to
-			 * invalid or frozen, and neither of those can match priorXmax.)
-			 */
-			if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
-									 priorXmax))
-			{
-				ReleaseBuffer(buffer);
-				return false;
-			}
-
-			/* otherwise xmin should not be dirty... */
-			if (TransactionIdIsValid(SnapshotDirty.xmin))
-				elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
-
-			/*
-			 * If tuple is being updated by other transaction then we have to
-			 * wait for its commit/abort, or die trying.
-			 */
-			if (TransactionIdIsValid(SnapshotDirty.xmax))
-			{
-				ReleaseBuffer(buffer);
-				switch (wait_policy)
-				{
-					case LockWaitBlock:
-						XactLockTableWait(SnapshotDirty.xmax,
-										  relation, &tuple.t_self,
-										  XLTW_FetchUpdated);
-						break;
-					case LockWaitSkip:
-						if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
-							return false;	/* skip instead of waiting */
-						break;
-					case LockWaitError:
-						if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
-							ereport(ERROR,
-									(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
-									 errmsg("could not obtain lock on row in relation \"%s\"",
-											RelationGetRelationName(relation))));
-						break;
-				}
-				continue;		/* loop back to repeat heap_fetch */
-			}
-
-			/*
-			 * If tuple was inserted by our own transaction, we have to check
-			 * cmin against es_output_cid: cmin >= current CID means our
-			 * command cannot see the tuple, so we should ignore it. Otherwise
-			 * heap_lock_tuple() will throw an error, and so would any later
-			 * attempt to update or delete the tuple.  (We need not check cmax
-			 * because HeapTupleSatisfiesDirty will consider a tuple deleted
-			 * by our transaction dead, regardless of cmax.) We just checked
-			 * that priorXmax == xmin, so we can test that variable instead of
-			 * doing HeapTupleHeaderGetXmin again.
-			 */
-			if (TransactionIdIsCurrentTransactionId(priorXmax) &&
-				HeapTupleHeaderGetCmin(tuple.t_data) >= estate->es_output_cid)
-			{
-				ReleaseBuffer(buffer);
-				return false;
-			}
-
-			/*
-			 * This is a live tuple, so now try to lock it.
-			 */
-			test = heap_lock_tuple(relation, &tuple,
-								   estate->es_output_cid,
-								   lockmode, wait_policy,
-								   false, &buffer, &hufd);
-			/* We now have two pins on the buffer, get rid of one */
-			ReleaseBuffer(buffer);
-
-			switch (test)
-			{
-				case HeapTupleSelfUpdated:
-
-					/*
-					 * The target tuple was already updated or deleted by the
-					 * current command, or by a later command in the current
-					 * transaction.  We *must* ignore the tuple in the former
-					 * case, so as to avoid the "Halloween problem" of
-					 * repeated update attempts.  In the latter case it might
-					 * be sensible to fetch the updated tuple instead, but
-					 * doing so would require changing heap_update and
-					 * heap_delete to not complain about updating "invisible"
-					 * tuples, which seems pretty scary (heap_lock_tuple will
-					 * not complain, but few callers expect
-					 * HeapTupleInvisible, and we're not one of them).  So for
-					 * now, treat the tuple as deleted and do not process.
-					 */
-					ReleaseBuffer(buffer);
-					return false;
-
-				case HeapTupleMayBeUpdated:
-					/* successfully locked */
-					break;
-
-				case HeapTupleUpdated:
-					ReleaseBuffer(buffer);
-					if (IsolationUsesXactSnapshot())
-						ereport(ERROR,
-								(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-								 errmsg("could not serialize access due to concurrent update")));
-					if (ItemPointerIndicatesMovedPartitions(&hufd.ctid))
-						ereport(ERROR,
-								(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-								 errmsg("tuple to be locked was already moved to another partition due to concurrent update")));
-
-					/* Should not encounter speculative tuple on recheck */
-					Assert(!HeapTupleHeaderIsSpeculative(tuple.t_data));
-					if (!ItemPointerEquals(&hufd.ctid, &tuple.t_self))
-					{
-						/* it was updated, so look at the updated version */
-						tuple.t_self = hufd.ctid;
-						/* updated row should have xmin matching this xmax */
-						priorXmax = hufd.xmax;
-						continue;
-					}
-					/* tuple was deleted, so give up */
-					return false;
-
-				case HeapTupleWouldBlock:
-					ReleaseBuffer(buffer);
-					return false;
-
-				case HeapTupleInvisible:
-					elog(ERROR, "attempted to lock invisible tuple");
-					break;
-
-				default:
-					ReleaseBuffer(buffer);
-					elog(ERROR, "unrecognized heap_lock_tuple status: %u",
-						 test);
-					return false;	/* keep compiler quiet */
-			}
-
-			/*
-			 * We got tuple - store it for use by the recheck query.
-			 */
-			ExecStorePinnedBufferHeapTuple(&tuple, slot, buffer);
-			ExecMaterializeSlot(slot);
-			break;
-		}
-
-		/*
-		 * If the referenced slot was actually empty, the latest version of
-		 * the row must have been deleted, so we need do nothing.
-		 */
-		if (tuple.t_data == NULL)
-		{
-			ReleaseBuffer(buffer);
-			return false;
-		}
-
-		/*
-		 * As above, if xmin isn't what we're expecting, do nothing.
-		 */
-		if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
-								 priorXmax))
-		{
-			ReleaseBuffer(buffer);
-			return false;
-		}
-
-		/*
-		 * If we get here, the tuple was found but failed SnapshotDirty.
-		 * Assuming the xmin is either a committed xact or our own xact (as it
-		 * certainly should be if we're trying to modify the tuple), this must
-		 * mean that the row was updated or deleted by either a committed xact
-		 * or our own xact.  If it was deleted, we can ignore it; if it was
-		 * updated then chain up to the next version and repeat the whole
-		 * process.
-		 *
-		 * As above, it should be safe to examine xmax and t_ctid without the
-		 * buffer content lock, because they can't be changing.
-		 */
-
-		/* check whether next version would be in a different partition */
-		if (HeapTupleHeaderIndicatesMovedPartitions(tuple.t_data))
-			ereport(ERROR,
-					(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-					 errmsg("tuple to be locked was already moved to another partition due to concurrent update")));
-
-		/* check whether tuple has been deleted */
-		if (ItemPointerEquals(&tuple.t_self, &tuple.t_data->t_ctid))
-		{
-			/* deleted, so forget about it */
-			ReleaseBuffer(buffer);
-			return false;
-		}
-
-		/* updated, so look at the updated row */
-		tuple.t_self = tuple.t_data->t_ctid;
-		/* updated row should have xmin matching this xmax */
-		priorXmax = HeapTupleHeaderGetUpdateXid(tuple.t_data);
-		ReleaseBuffer(buffer);
-		/* loop back to fetch next in chain */
-	}
-
-	/* signal success */
-	return true;
-}
-
 /*
  * EvalPlanQualInit -- initialize during creation of a plan state node
  * that might need to invoke EPQ processing.
@@ -2911,8 +2642,8 @@ EvalPlanQualFetchRowMarks(EPQState *epqstate)
 				Buffer		buffer;
 
 				tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
-				if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
-								false, NULL))
+				if (!heap_fetch(erm->relation, &tuple.t_self, SnapshotAny,
+								&tuple, &buffer, NULL))
 					elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
 
 				/* successful, store tuple */
diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c
index 95dfc4987de..73090d47d19 100644
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -15,7 +15,6 @@
 #include "postgres.h"
 
 #include "access/genam.h"
-#include "access/heapam.h"
 #include "access/relscan.h"
 #include "access/tableam.h"
 #include "access/transam.h"
@@ -166,25 +165,18 @@ retry:
 	/* Found tuple, try to lock it in the lockmode. */
 	if (found)
 	{
-		Buffer		buf;
 		HeapUpdateFailureData hufd;
 		HTSU_Result res;
-		HeapTupleData locktup;
-		HeapTupleTableSlot *hslot = (HeapTupleTableSlot *)outslot;
-
-		/* Only a heap tuple has item pointers. */
-		Assert(TTS_IS_HEAPTUPLE(outslot) || TTS_IS_BUFFERTUPLE(outslot));
-		ItemPointerCopy(&hslot->tuple->t_self, &locktup.t_self);
 
 		PushActiveSnapshot(GetLatestSnapshot());
 
-		res = heap_lock_tuple(rel, &locktup, GetCurrentCommandId(false),
-							  lockmode,
-							  LockWaitBlock,
-							  false /* don't follow updates */ ,
-							  &buf, &hufd);
-		/* the tuple slot already has the buffer pinned */
-		ReleaseBuffer(buf);
+		res = table_lock_tuple(rel, &(outslot->tts_tid), GetLatestSnapshot(),
+							   outslot,
+							   GetCurrentCommandId(false),
+							   lockmode,
+							   LockWaitBlock,
+							   0 /* don't follow updates */ ,
+							   &hufd);
 
 		PopActiveSnapshot();
 
@@ -203,6 +195,12 @@ retry:
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
 							 errmsg("concurrent update, retrying")));
 				goto retry;
+			case HeapTupleDeleted:
+				/* XXX: Improve handling here */
+				ereport(LOG,
+						(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+						 errmsg("concurrent delete, retrying")));
+				goto retry;
 			case HeapTupleInvisible:
 				elog(ERROR, "attempted to lock invisible tuple");
 				break;
@@ -330,25 +328,18 @@ retry:
 	/* Found tuple, try to lock it in the lockmode. */
 	if (found)
 	{
-		Buffer		buf;
 		HeapUpdateFailureData hufd;
 		HTSU_Result res;
-		HeapTupleData locktup;
-		HeapTupleTableSlot *hslot = (HeapTupleTableSlot *)outslot;
-
-		/* Only a heap tuple has item pointers. */
-		Assert(TTS_IS_HEAPTUPLE(outslot) || TTS_IS_BUFFERTUPLE(outslot));
-		ItemPointerCopy(&hslot->tuple->t_self, &locktup.t_self);
 
 		PushActiveSnapshot(GetLatestSnapshot());
 
-		res = heap_lock_tuple(rel, &locktup, GetCurrentCommandId(false),
-							  lockmode,
-							  LockWaitBlock,
-							  false /* don't follow updates */ ,
-							  &buf, &hufd);
-		/* the tuple slot already has the buffer pinned */
-		ReleaseBuffer(buf);
+		res = table_lock_tuple(rel, &(outslot->tts_tid), GetLatestSnapshot(),
+							   outslot,
+							   GetCurrentCommandId(false),
+							   lockmode,
+							   LockWaitBlock,
+							   0 /* don't follow updates */ ,
+							   &hufd);
 
 		PopActiveSnapshot();
 
@@ -367,6 +358,12 @@ retry:
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
 							 errmsg("concurrent update, retrying")));
 				goto retry;
+			case HeapTupleDeleted:
+				/* XXX: Improve handling here */
+				ereport(LOG,
+						(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+						 errmsg("concurrent delete, retrying")));
+				goto retry;
 			case HeapTupleInvisible:
 				elog(ERROR, "attempted to lock invisible tuple");
 				break;
@@ -392,7 +389,6 @@ void
 ExecSimpleRelationInsert(EState *estate, TupleTableSlot *slot)
 {
 	bool		skip_tuple = false;
-	HeapTuple	tuple;
 	ResultRelInfo *resultRelInfo = estate->es_result_relation_info;
 	Relation	rel = resultRelInfo->ri_RelationDesc;
 
@@ -419,16 +415,12 @@ ExecSimpleRelationInsert(EState *estate, TupleTableSlot *slot)
 		if (resultRelInfo->ri_PartitionCheck)
 			ExecPartitionCheck(resultRelInfo, slot, estate, true);
 
-		/* Materialize slot into a tuple that we can scribble upon. */
-		tuple = ExecFetchSlotHeapTuple(slot, true, NULL);
-
 		/* OK, store the tuple and create index entries for it */
-		simple_heap_insert(rel, tuple);
-		ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
+		table_insert(resultRelInfo->ri_RelationDesc, slot,
+					 GetCurrentCommandId(true), 0, NULL);
 
 		if (resultRelInfo->ri_NumIndices > 0)
-			recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self),
-												   estate, false, NULL,
+			recheckIndexes = ExecInsertIndexTuples(slot, estate, false, NULL,
 												   NIL);
 
 		/* AFTER ROW INSERT Triggers */
@@ -456,13 +448,9 @@ ExecSimpleRelationUpdate(EState *estate, EPQState *epqstate,
 						 TupleTableSlot *searchslot, TupleTableSlot *slot)
 {
 	bool		skip_tuple = false;
-	HeapTuple	tuple;
 	ResultRelInfo *resultRelInfo = estate->es_result_relation_info;
 	Relation	rel = resultRelInfo->ri_RelationDesc;
-	HeapTupleTableSlot *hsearchslot = (HeapTupleTableSlot *)searchslot;
-
-	/* We expect the searchslot to contain a heap tuple. */
-	Assert(TTS_IS_HEAPTUPLE(searchslot) || TTS_IS_BUFFERTUPLE(searchslot));
+	ItemPointer tid = &(searchslot->tts_tid);
 
 	/* For now we support only tables. */
 	Assert(rel->rd_rel->relkind == RELKIND_RELATION);
@@ -474,14 +462,14 @@ ExecSimpleRelationUpdate(EState *estate, EPQState *epqstate,
 		resultRelInfo->ri_TrigDesc->trig_update_before_row)
 	{
 		if (!ExecBRUpdateTriggers(estate, epqstate, resultRelInfo,
-								  &hsearchslot->tuple->t_self,
-								  NULL, slot))
+								  tid, NULL, slot))
 			skip_tuple = true;		/* "do nothing" */
 	}
 
 	if (!skip_tuple)
 	{
 		List	   *recheckIndexes = NIL;
+		bool		update_indexes;
 
 		/* Check the constraints of the tuple */
 		if (rel->rd_att->constr)
@@ -489,23 +477,16 @@ ExecSimpleRelationUpdate(EState *estate, EPQState *epqstate,
 		if (resultRelInfo->ri_PartitionCheck)
 			ExecPartitionCheck(resultRelInfo, slot, estate, true);
 
-		/* Materialize slot into a tuple that we can scribble upon. */
-		tuple = ExecFetchSlotHeapTuple(slot, true, NULL);
+		simple_table_update(rel, tid, slot,
+							estate->es_snapshot, &update_indexes);
 
-		/* OK, update the tuple and index entries for it */
-		simple_heap_update(rel, &hsearchslot->tuple->t_self, tuple);
-		ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
-
-		if (resultRelInfo->ri_NumIndices > 0 &&
-			!HeapTupleIsHeapOnly(tuple))
-			recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self),
-												   estate, false, NULL,
+		if (resultRelInfo->ri_NumIndices > 0 && update_indexes)
+			recheckIndexes = ExecInsertIndexTuples(slot, estate, false, NULL,
 												   NIL);
 
 		/* AFTER ROW UPDATE Triggers */
 		ExecARUpdateTriggers(estate, resultRelInfo,
-							 &(tuple->t_self),
-							 NULL, slot,
+							 tid, NULL, slot,
 							 recheckIndexes, NULL);
 
 		list_free(recheckIndexes);
@@ -525,7 +506,7 @@ ExecSimpleRelationDelete(EState *estate, EPQState *epqstate,
 	bool		skip_tuple = false;
 	ResultRelInfo *resultRelInfo = estate->es_result_relation_info;
 	Relation	rel = resultRelInfo->ri_RelationDesc;
-	HeapTupleTableSlot *hsearchslot = (HeapTupleTableSlot *)searchslot;
+	ItemPointer tid = &(searchslot->tts_tid);
 
 	/* For now we support only tables and heap tuples. */
 	Assert(rel->rd_rel->relkind == RELKIND_RELATION);
@@ -538,23 +519,18 @@ ExecSimpleRelationDelete(EState *estate, EPQState *epqstate,
 		resultRelInfo->ri_TrigDesc->trig_delete_before_row)
 	{
 		skip_tuple = !ExecBRDeleteTriggers(estate, epqstate, resultRelInfo,
-										   &hsearchslot->tuple->t_self,
-										   NULL, NULL);
+										   tid, NULL, NULL);
 
 	}
 
 	if (!skip_tuple)
 	{
-		List	   *recheckIndexes = NIL;
-
 		/* OK, delete the tuple */
-		simple_heap_delete(rel, &hsearchslot->tuple->t_self);
+		simple_table_delete(rel, tid, estate->es_snapshot);
 
 		/* AFTER ROW DELETE Triggers */
 		ExecARDeleteTriggers(estate, resultRelInfo,
-							 &hsearchslot->tuple->t_self, NULL, NULL);
-
-		list_free(recheckIndexes);
+							 tid, NULL, NULL);
 	}
 }
 
diff --git a/src/backend/executor/nodeLockRows.c b/src/backend/executor/nodeLockRows.c
index 76f0f9d66e5..91f46b88ed8 100644
--- a/src/backend/executor/nodeLockRows.c
+++ b/src/backend/executor/nodeLockRows.c
@@ -23,6 +23,7 @@
 
 #include "access/heapam.h"
 #include "access/htup_details.h"
+#include "access/tableam.h"
 #include "access/xact.h"
 #include "executor/executor.h"
 #include "executor/nodeLockRows.h"
@@ -82,8 +83,7 @@ lnext:
 		ExecRowMark *erm = aerm->rowmark;
 		Datum		datum;
 		bool		isNull;
-		HeapTupleData tuple;
-		Buffer		buffer;
+		ItemPointerData tid;
 		HeapUpdateFailureData hufd;
 		LockTupleMode lockmode;
 		HTSU_Result test;
@@ -161,7 +161,7 @@ lnext:
 		}
 
 		/* okay, try to lock the tuple */
-		tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
+		tid = *((ItemPointer) DatumGetPointer(datum));
 		switch (erm->markType)
 		{
 			case ROW_MARK_EXCLUSIVE:
@@ -182,11 +182,13 @@ lnext:
 				break;
 		}
 
-		test = heap_lock_tuple(erm->relation, &tuple,
-							   estate->es_output_cid,
-							   lockmode, erm->waitPolicy, true,
-							   &buffer, &hufd);
-		ReleaseBuffer(buffer);
+		test = table_lock_tuple(erm->relation, &tid, estate->es_snapshot,
+								markSlot, estate->es_output_cid,
+								lockmode, erm->waitPolicy,
+								(IsolationUsesXactSnapshot() ? 0 : TUPLE_LOCK_FLAG_FIND_LAST_VERSION)
+								| TUPLE_LOCK_FLAG_LOCK_UPDATE_IN_PROGRESS,
+								&hufd);
+
 		switch (test)
 		{
 			case HeapTupleWouldBlock:
@@ -213,6 +215,15 @@ lnext:
 
 			case HeapTupleMayBeUpdated:
 				/* got the lock successfully */
+				if (hufd.traversed)
+				{
+					/* locked tuple saved in markSlot for EvalPlanQual testing below */
+
+					/* Remember we need to do EPQ testing */
+					epq_needed = true;
+
+					/* Continue loop until we have all target tuples */
+				}
 				break;
 
 			case HeapTupleUpdated:
@@ -220,37 +231,19 @@ lnext:
 					ereport(ERROR,
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
 							 errmsg("could not serialize access due to concurrent update")));
-				if (ItemPointerIndicatesMovedPartitions(&hufd.ctid))
+				/* skip lock */
+				goto lnext;
+
+			case HeapTupleDeleted:
+				if (IsolationUsesXactSnapshot())
 					ereport(ERROR,
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-							 errmsg("tuple to be locked was already moved to another partition due to concurrent update")));
-
-				if (ItemPointerEquals(&hufd.ctid, &tuple.t_self))
-				{
-					/* Tuple was deleted, so don't return it */
-					goto lnext;
-				}
-
-				/* updated, so fetch and lock the updated version */
-				if (!EvalPlanQualFetch(estate, erm->relation,
-									   lockmode, erm->waitPolicy,
-									   &hufd.ctid, hufd.xmax,
-									   markSlot))
-				{
-					/*
-					 * Tuple was deleted; or it's locked and we're under SKIP
-					 * LOCKED policy, so don't return it
-					 */
-					goto lnext;
-				}
-				/* remember the actually locked tuple's TID */
-				tuple.t_self = markSlot->tts_tid;
-
-				/* Remember we need to do EPQ testing */
-				epq_needed = true;
-
-				/* Continue loop until we have all target tuples */
-				break;
+							 errmsg("could not serialize access due to concurrent update")));
+				/*
+				 * Tuple was deleted; or it's locked and we're under SKIP
+				 * LOCKED policy, so don't return it
+				 */
+				goto lnext;
 
 			case HeapTupleInvisible:
 				elog(ERROR, "attempted to lock invisible tuple");
@@ -262,7 +255,7 @@ lnext:
 		}
 
 		/* Remember locked tuple's TID for EPQ testing and WHERE CURRENT OF */
-		erm->curCtid = tuple.t_self;
+		erm->curCtid = tid;
 	}
 
 	/*
@@ -305,8 +298,8 @@ lnext:
 
 			/* okay, fetch the tuple */
 			tuple.t_self = erm->curCtid;
-			if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
-							false, NULL))
+			if (!heap_fetch(erm->relation, &tuple.t_self, SnapshotAny, &tuple, &buffer,
+							NULL))
 				elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
 			ExecStorePinnedBufferHeapTuple(&tuple, markSlot, buffer);
 			ExecMaterializeSlot(markSlot);
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index e316ff99012..5b079d8302a 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -42,6 +42,7 @@
 #include "access/tableam.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"
+#include "catalog/pg_am.h"
 #include "commands/trigger.h"
 #include "executor/execPartition.h"
 #include "executor/executor.h"
@@ -190,31 +191,33 @@ ExecProcessReturning(ResultRelInfo *resultRelInfo,
  */
 static void
 ExecCheckHeapTupleVisible(EState *estate,
-						  HeapTuple tuple,
-						  Buffer buffer)
+						  Relation rel,
+						  TupleTableSlot *slot)
 {
 	if (!IsolationUsesXactSnapshot())
 		return;
 
-	/*
-	 * We need buffer pin and lock to call HeapTupleSatisfiesVisibility.
-	 * Caller should be holding pin, but not lock.
-	 */
-	LockBuffer(buffer, BUFFER_LOCK_SHARE);
-	if (!HeapTupleSatisfiesVisibility(tuple, estate->es_snapshot, buffer))
+	if (!table_tuple_satisfies_snapshot(rel, slot, estate->es_snapshot))
 	{
+		Datum		xminDatum;
+		TransactionId xmin;
+		bool		isnull;
+
+		xminDatum = slot_getsysattr(slot, MinTransactionIdAttributeNumber, &isnull);
+		Assert(!isnull);
+		xmin = DatumGetTransactionId(xminDatum);
+
 		/*
 		 * We should not raise a serialization failure if the conflict is
 		 * against a tuple inserted by our own transaction, even if it's not
 		 * visible to our snapshot.  (This would happen, for example, if
 		 * conflicting keys are proposed for insertion in a single command.)
 		 */
-		if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple->t_data)))
+		if (!TransactionIdIsCurrentTransactionId(xmin))
 			ereport(ERROR,
 					(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
 					 errmsg("could not serialize access due to concurrent update")));
 	}
-	LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
 }
 
 /*
@@ -223,7 +226,8 @@ ExecCheckHeapTupleVisible(EState *estate,
 static void
 ExecCheckTIDVisible(EState *estate,
 					ResultRelInfo *relinfo,
-					ItemPointer tid)
+					ItemPointer tid,
+					TupleTableSlot *tempSlot)
 {
 	Relation	rel = relinfo->ri_RelationDesc;
 	Buffer		buffer;
@@ -234,10 +238,10 @@ ExecCheckTIDVisible(EState *estate,
 		return;
 
 	tuple.t_self = *tid;
-	if (!heap_fetch(rel, SnapshotAny, &tuple, &buffer, false, NULL))
+	if (!heap_fetch(rel, &tuple.t_self, SnapshotAny, &tuple, &buffer, NULL))
 		elog(ERROR, "failed to fetch conflicting tuple for ON CONFLICT");
-	ExecCheckHeapTupleVisible(estate, &tuple, buffer);
-	ReleaseBuffer(buffer);
+	ExecStorePinnedBufferHeapTuple(&tuple, tempSlot, buffer);
+	ExecCheckHeapTupleVisible(estate, rel, tempSlot);
 }
 
 /* ----------------------------------------------------------------
@@ -319,7 +323,6 @@ ExecInsert(ModifyTableState *mtstate,
 	else
 	{
 		WCOKind		wco_kind;
-		HeapTuple	inserttuple;
 
 		/*
 		 * Constraints might reference the tableoid column, so (re-)initialize
@@ -417,16 +420,19 @@ ExecInsert(ModifyTableState *mtstate,
 					 * In case of ON CONFLICT DO NOTHING, do nothing. However,
 					 * verify that the tuple is visible to the executor's MVCC
 					 * snapshot at higher isolation levels.
+					 *
+					 * FIXME: Either comment or replace usage of
+					 * ExecGetReturningSlot(). Need a slot that's compatible
+					 * with the resultRelInfo table.
 					 */
 					Assert(onconflict == ONCONFLICT_NOTHING);
-					ExecCheckTIDVisible(estate, resultRelInfo, &conflictTid);
+					ExecCheckTIDVisible(estate, resultRelInfo, &conflictTid,
+										ExecGetReturningSlot(estate, resultRelInfo));
 					InstrCountTuples2(&mtstate->ps, 1);
 					return NULL;
 				}
 			}
 
-			inserttuple = ExecFetchSlotHeapTuple(slot, true, NULL);
-
 			/*
 			 * Before we start insertion proper, acquire our "speculative
 			 * insertion lock".  Others can use that to wait for us to decide
@@ -434,26 +440,23 @@ ExecInsert(ModifyTableState *mtstate,
 			 * waiting for the whole transaction to complete.
 			 */
 			specToken = SpeculativeInsertionLockAcquire(GetCurrentTransactionId());
-			HeapTupleHeaderSetSpeculativeToken(inserttuple->t_data, specToken);
 
 			/* insert the tuple, with the speculative token */
-			heap_insert(resultRelationDesc, inserttuple,
-						estate->es_output_cid,
-						HEAP_INSERT_SPECULATIVE,
-						NULL);
+			table_insert_speculative(resultRelationDesc, slot,
+									 estate->es_output_cid,
+									 HEAP_INSERT_SPECULATIVE,
+									 NULL,
+									 specToken);
 			slot->tts_tableOid = RelationGetRelid(resultRelationDesc);
-			ItemPointerCopy(&inserttuple->t_self, &slot->tts_tid);
 
 			/* insert index entries for tuple */
-			recheckIndexes = ExecInsertIndexTuples(slot, &(inserttuple->t_self),
+			recheckIndexes = ExecInsertIndexTuples(slot,
 												   estate, true, &specConflict,
 												   arbiterIndexes);
 
 			/* adjust the tuple's state accordingly */
-			if (!specConflict)
-				heap_finish_speculative(resultRelationDesc, inserttuple);
-			else
-				heap_abort_speculative(resultRelationDesc, inserttuple);
+			table_complete_speculative(resultRelationDesc, slot,
+									   specToken, specConflict);
 
 			/*
 			 * Wake up anyone waiting for our decision.  They will re-check
@@ -481,21 +484,15 @@ ExecInsert(ModifyTableState *mtstate,
 		{
 			/*
 			 * insert the tuple normally.
-			 *
-			 * Note: heap_insert returns the tid (location) of the new tuple
-			 * in the t_self field.
 			 */
-			inserttuple = ExecFetchSlotHeapTuple(slot, true, NULL);
-			heap_insert(resultRelationDesc, inserttuple,
-						estate->es_output_cid,
-						0, NULL);
+			table_insert(resultRelationDesc, slot,
+						 estate->es_output_cid,
+						 0, NULL);
 			slot->tts_tableOid = RelationGetRelid(resultRelationDesc);
-			ItemPointerCopy(&inserttuple->t_self, &slot->tts_tid);
 
 			/* insert index entries for tuple */
 			if (resultRelInfo->ri_NumIndices > 0)
-				recheckIndexes = ExecInsertIndexTuples(slot, &(inserttuple->t_self),
-													   estate, false, NULL,
+				recheckIndexes = ExecInsertIndexTuples(slot, estate, false, NULL,
 													   NIL);
 		}
 	}
@@ -671,12 +668,58 @@ ExecDelete(ModifyTableState *mtstate,
 		 * mode transactions.
 		 */
 ldelete:;
-		result = heap_delete(resultRelationDesc, tupleid,
-							 estate->es_output_cid,
-							 estate->es_crosscheck_snapshot,
-							 true /* wait for commit */ ,
-							 &hufd,
-							 changingPart);
+		result = table_delete(resultRelationDesc, tupleid,
+							  estate->es_output_cid,
+							  estate->es_snapshot,
+							  estate->es_crosscheck_snapshot,
+							  true /* wait for commit */ ,
+							  &hufd,
+							  changingPart);
+
+		if (result == HeapTupleUpdated && !IsolationUsesXactSnapshot())
+		{
+			EvalPlanQualBegin(epqstate, estate);
+			slot = EvalPlanQualSlot(epqstate, resultRelationDesc, resultRelInfo->ri_RangeTableIndex);
+
+			result = table_lock_tuple(resultRelationDesc, tupleid,
+									  estate->es_snapshot,
+									  slot, estate->es_output_cid,
+									  LockTupleExclusive, LockWaitBlock,
+									  TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
+									  &hufd);
+			/*hari FIXME*/
+			/*Assert(result != HeapTupleUpdated && hufd.traversed);*/
+			if (result == HeapTupleMayBeUpdated)
+			{
+				TupleTableSlot *epqslot;
+
+				epqslot = EvalPlanQual(estate,
+									   epqstate,
+									   resultRelationDesc,
+									   resultRelInfo->ri_RangeTableIndex,
+									   slot);
+				if (TupIsNull(epqslot))
+				{
+					/* Tuple no more passing quals, exiting... */
+					return NULL;
+				}
+
+				/**/
+				if (epqreturnslot)
+				{
+					*epqreturnslot = epqslot;
+					return NULL;
+				}
+
+				goto ldelete;
+			}
+			else if (result == HeapTupleInvisible)
+			{
+				/* tuple is not visible; nothing to do */
+				return NULL;
+			}
+		}
+
 		switch (result)
 		{
 			case HeapTupleSelfUpdated:
@@ -722,39 +765,16 @@ ldelete:;
 					ereport(ERROR,
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
 							 errmsg("could not serialize access due to concurrent update")));
-				if (ItemPointerIndicatesMovedPartitions(&hufd.ctid))
+				else
+					/* shouldn't get there */
+					elog(ERROR, "wrong heap_delete status: %u", result);
+				break;
+
+			case HeapTupleDeleted:
+				if (IsolationUsesXactSnapshot())
 					ereport(ERROR,
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-							 errmsg("tuple to be deleted was already moved to another partition due to concurrent update")));
-
-				if (!ItemPointerEquals(tupleid, &hufd.ctid))
-				{
-					TupleTableSlot *my_epqslot;
-
-					my_epqslot = EvalPlanQual(estate,
-											  epqstate,
-											  resultRelationDesc,
-											  resultRelInfo->ri_RangeTableIndex,
-											  LockTupleExclusive,
-											  &hufd.ctid,
-											  hufd.xmax);
-					if (!TupIsNull(my_epqslot))
-					{
-						*tupleid = hufd.ctid;
-
-						/*
-						 * If requested, skip delete and pass back the updated
-						 * row.
-						 */
-						if (epqreturnslot)
-						{
-							*epqreturnslot = my_epqslot;
-							return NULL;
-						}
-						else
-							goto ldelete;
-					}
-				}
+							 errmsg("could not serialize access due to concurrent delete")));
 				/* tuple already deleted; nothing to do */
 				return NULL;
 
@@ -841,8 +861,8 @@ ldelete:;
 				deltuple = &bslot->base.tupdata;
 
 				deltuple->t_self = *tupleid;
-				if (!heap_fetch(resultRelationDesc, SnapshotAny,
-								deltuple, &buffer, false, NULL))
+				if (!heap_fetch(resultRelationDesc, &deltuple->t_self, SnapshotAny,
+								deltuple, &buffer, NULL))
 					elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
 
 				ExecStorePinnedBufferHeapTuple(deltuple, slot, buffer);
@@ -897,7 +917,6 @@ ExecUpdate(ModifyTableState *mtstate,
 		   EState *estate,
 		   bool canSetTag)
 {
-	HeapTuple	updatetuple;
 	ResultRelInfo *resultRelInfo;
 	Relation	resultRelationDesc;
 	HTSU_Result result;
@@ -925,7 +944,7 @@ ExecUpdate(ModifyTableState *mtstate,
 	{
 		if (!ExecBRUpdateTriggers(estate, epqstate, resultRelInfo,
 								  tupleid, oldtuple, slot))
-			return NULL;        /* "do nothing" */
+			return NULL;		/* "do nothing" */
 	}
 
 	/* INSTEAD OF ROW UPDATE Triggers */
@@ -934,7 +953,7 @@ ExecUpdate(ModifyTableState *mtstate,
 	{
 		if (!ExecIRUpdateTriggers(estate, resultRelInfo,
 								  oldtuple, slot))
-			return NULL;        /* "do nothing" */
+			return NULL;		/* "do nothing" */
 	}
 	else if (resultRelInfo->ri_FdwRoutine)
 	{
@@ -960,6 +979,7 @@ ExecUpdate(ModifyTableState *mtstate,
 	{
 		LockTupleMode lockmode;
 		bool		partition_constraint_failed;
+		bool		update_indexes;
 
 		/*
 		 * Constraints might reference the tableoid column, so (re-)initialize
@@ -978,6 +998,9 @@ ExecUpdate(ModifyTableState *mtstate,
 		 */
 lreplace:;
 
+		/* ensure slot is independent, consider e.g. EPQ */
+		ExecMaterializeSlot(slot);
+
 		/*
 		 * If partition constraint fails, this row might get moved to another
 		 * partition, in which case we should check the RLS CHECK policy just
@@ -1145,14 +1168,53 @@ lreplace:;
 		 * needed for referential integrity updates in transaction-snapshot
 		 * mode transactions.
 		 */
-		updatetuple = ExecFetchSlotHeapTuple(slot, true, NULL);
-		result = heap_update(resultRelationDesc, tupleid,
-							 updatetuple,
-							 estate->es_output_cid,
-							 estate->es_crosscheck_snapshot,
-							 true /* wait for commit */ ,
-							 &hufd, &lockmode);
-		ItemPointerCopy(&updatetuple->t_self, &slot->tts_tid);
+		result = table_update(resultRelationDesc, tupleid, slot,
+							  estate->es_output_cid,
+							  estate->es_snapshot,
+							  estate->es_crosscheck_snapshot,
+							  true /* wait for commit */ ,
+							  &hufd, &lockmode, &update_indexes);
+
+		if (result == HeapTupleUpdated && !IsolationUsesXactSnapshot())
+		{
+			TupleTableSlot *inputslot;
+
+			EvalPlanQualBegin(epqstate, estate);
+
+			inputslot = EvalPlanQualSlot(epqstate, resultRelationDesc, resultRelInfo->ri_RangeTableIndex);
+			ExecCopySlot(inputslot, slot);
+
+			result = table_lock_tuple(resultRelationDesc, tupleid,
+									  estate->es_snapshot,
+									  inputslot, estate->es_output_cid,
+									  lockmode, LockWaitBlock,
+									  TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
+									  &hufd);
+			/* hari FIXME*/
+			/*Assert(result != HeapTupleUpdated && hufd.traversed);*/
+			if (result == HeapTupleMayBeUpdated)
+			{
+				TupleTableSlot *epqslot;
+
+				epqslot = EvalPlanQual(estate,
+									   epqstate,
+									   resultRelationDesc,
+									   resultRelInfo->ri_RangeTableIndex,
+									   inputslot);
+				if (TupIsNull(epqslot))
+				{
+					/* Tuple no more passing quals, exiting... */
+					return NULL;
+				}
+				slot = ExecFilterJunk(resultRelInfo->ri_junkFilter, epqslot);
+				goto lreplace;
+			}
+			else if (result == HeapTupleInvisible)
+			{
+				/* tuple is not visible; nothing to do */
+				return NULL;
+			}
+		}
 
 		switch (result)
 		{
@@ -1194,33 +1256,22 @@ lreplace:;
 				break;
 
 			case HeapTupleUpdated:
+
+				/*
+				 * The lower level isolation case for HeapTupleUpdated is
+				 * handled above.
+				 */
+				Assert(IsolationUsesXactSnapshot());
+				ereport(ERROR,
+						(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+						 errmsg("could not serialize access due to concurrent update")));
+				break;
+
+			case HeapTupleDeleted:
 				if (IsolationUsesXactSnapshot())
 					ereport(ERROR,
 							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-							 errmsg("could not serialize access due to concurrent update")));
-				if (ItemPointerIndicatesMovedPartitions(&hufd.ctid))
-					ereport(ERROR,
-							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
-							 errmsg("tuple to be updated was already moved to another partition due to concurrent update")));
-
-				if (!ItemPointerEquals(tupleid, &hufd.ctid))
-				{
-					TupleTableSlot *epqslot;
-
-					epqslot = EvalPlanQual(estate,
-										   epqstate,
-										   resultRelationDesc,
-										   resultRelInfo->ri_RangeTableIndex,
-										   lockmode,
-										   &hufd.ctid,
-										   hufd.xmax);
-					if (!TupIsNull(epqslot))
-					{
-						*tupleid = hufd.ctid;
-						slot = ExecFilterJunk(resultRelInfo->ri_junkFilter, epqslot);
-						goto lreplace;
-					}
-				}
+							 errmsg("could not serialize access due to concurrent delete")));
 				/* tuple already deleted; nothing to do */
 				return NULL;
 
@@ -1241,13 +1292,12 @@ lreplace:;
 		 * insert index entries for tuple
 		 *
 		 * Note: heap_update returns the tid (location) of the new tuple in
-		 * the t_self field.
+		 * the t_self field.  FIXME
 		 *
 		 * If it's a HOT update, we mustn't insert new index entries.
 		 */
-		if (resultRelInfo->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(updatetuple))
-			recheckIndexes = ExecInsertIndexTuples(slot, &(updatetuple->t_self),
-												   estate, false, NULL, NIL);
+		if (resultRelInfo->ri_NumIndices > 0 && update_indexes)
+			recheckIndexes = ExecInsertIndexTuples(slot, estate, false, NULL, NIL);
 	}
 
 	if (canSetTag)
@@ -1306,11 +1356,12 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 	Relation	relation = resultRelInfo->ri_RelationDesc;
 	ExprState  *onConflictSetWhere = resultRelInfo->ri_onConflict->oc_WhereClause;
 	TupleTableSlot *existing = resultRelInfo->ri_onConflict->oc_Existing;
-	HeapTupleData tuple;
 	HeapUpdateFailureData hufd;
 	LockTupleMode lockmode;
 	HTSU_Result test;
-	Buffer		buffer;
+	Datum		xminDatum;
+	TransactionId xmin;
+	bool		isnull;
 
 	/* Determine lock mode to use */
 	lockmode = ExecUpdateLockMode(estate, resultRelInfo);
@@ -1321,10 +1372,11 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 	 * previous conclusion that the tuple is conclusively committed is not
 	 * true anymore.
 	 */
-	tuple.t_self = *conflictTid;
-	test = heap_lock_tuple(relation, &tuple, estate->es_output_cid,
-						   lockmode, LockWaitBlock, false, &buffer,
-						   &hufd);
+	test = table_lock_tuple(relation, conflictTid,
+							estate->es_snapshot,
+							existing, estate->es_output_cid,
+							lockmode, LockWaitBlock, 0,
+							&hufd);
 	switch (test)
 	{
 		case HeapTupleMayBeUpdated:
@@ -1349,7 +1401,13 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 			 * that for SQL MERGE, an exception must be raised in the event of
 			 * an attempt to update the same row twice.
 			 */
-			if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple.t_data)))
+			xminDatum = slot_getsysattr(existing,
+										MinTransactionIdAttributeNumber,
+										&isnull);
+			Assert(!isnull);
+			xmin = DatumGetTransactionId(xminDatum);
+
+			if (TransactionIdIsCurrentTransactionId(xmin))
 				ereport(ERROR,
 						(errcode(ERRCODE_CARDINALITY_VIOLATION),
 						 errmsg("ON CONFLICT DO UPDATE command cannot affect row a second time"),
@@ -1390,7 +1448,16 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 			 * loop here, as the new version of the row might not conflict
 			 * anymore, or the conflicting tuple has actually been deleted.
 			 */
-			ReleaseBuffer(buffer);
+			ExecClearTuple(existing);
+			return false;
+
+		case HeapTupleDeleted:
+			if (IsolationUsesXactSnapshot())
+				ereport(ERROR,
+						(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+						 errmsg("could not serialize access due to concurrent delete")));
+
+			ExecClearTuple(existing);
 			return false;
 
 		default:
@@ -1412,10 +1479,7 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 	 * snapshot.  This is in line with the way UPDATE deals with newer tuple
 	 * versions.
 	 */
-	ExecCheckHeapTupleVisible(estate, &tuple, buffer);
-
-	/* Store target's existing tuple in the state's dedicated slot */
-	ExecStorePinnedBufferHeapTuple(&tuple, existing, buffer);
+	ExecCheckHeapTupleVisible(estate, relation, existing);
 
 	/*
 	 * Make tuple and any needed join variables available to ExecQual and
@@ -1470,7 +1534,7 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 	 */
 
 	/* Execute UPDATE with projection */
-	*returning = ExecUpdate(mtstate, &tuple.t_self, NULL,
+	*returning = ExecUpdate(mtstate, conflictTid, NULL,
 							resultRelInfo->ri_onConflict->oc_ProjSlot,
 							planSlot,
 							&mtstate->mt_epqstate, mtstate->ps.state,
diff --git a/src/backend/executor/nodeTidscan.c b/src/backend/executor/nodeTidscan.c
index 08872ef9b4f..b819cf2383e 100644
--- a/src/backend/executor/nodeTidscan.c
+++ b/src/backend/executor/nodeTidscan.c
@@ -376,7 +376,7 @@ TidNext(TidScanState *node)
 		if (node->tss_isCurrentOf)
 			heap_get_latest_tid(heapRelation, snapshot, &tuple->t_self);
 
-		if (heap_fetch(heapRelation, snapshot, tuple, &buffer, false, NULL))
+		if (heap_fetch(heapRelation, &tuple->t_self, snapshot, tuple, &buffer, NULL))
 		{
 			/*
 			 * Store the scanned tuple in the scan tuple slot of the scan
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index a369716ce31..02bfc914d11 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -35,32 +35,10 @@
 #define HEAP_INSERT_NO_LOGICAL	0x0010
 
 typedef struct BulkInsertStateData *BulkInsertState;
+struct HeapUpdateFailureData;
 
 #define MaxLockTupleMode	LockTupleExclusive
 
-/*
- * When heap_update, heap_delete, or heap_lock_tuple fail because the target
- * tuple is already outdated, they fill in this struct to provide information
- * to the caller about what happened.
- * ctid is the target's ctid link: it is the same as the target's TID if the
- * target was deleted, or the location of the replacement tuple if the target
- * was updated.
- * xmax is the outdating transaction's XID.  If the caller wants to visit the
- * replacement tuple, it must check that this matches before believing the
- * replacement is really a match.
- * cmax is the outdating command's CID, but only when the failure code is
- * HeapTupleSelfUpdated (i.e., something in the current transaction outdated
- * the tuple); otherwise cmax is zero.  (We make this restriction because
- * HeapTupleHeaderGetCmax doesn't work for tuples outdated in other
- * transactions.)
- */
-typedef struct HeapUpdateFailureData
-{
-	ItemPointerData ctid;
-	TransactionId xmax;
-	CommandId	cmax;
-} HeapUpdateFailureData;
-
 /*
  * Descriptor for heap table scans.
  */
@@ -149,8 +127,8 @@ extern HeapTuple heap_getnext(TableScanDesc scan, ScanDirection direction);
 extern bool heap_getnextslot(TableScanDesc sscan,
 			ScanDirection direction, struct TupleTableSlot *slot);
 
-extern bool heap_fetch(Relation relation, Snapshot snapshot,
-		   HeapTuple tuple, Buffer *userbuf, bool keep_buf,
+extern bool heap_fetch(Relation relation, ItemPointer tid, Snapshot snapshot,
+		   HeapTuple tuple, Buffer *userbuf,
 		   Relation stats_relation);
 extern bool heap_hot_search_buffer(ItemPointer tid, Relation relation,
 					   Buffer buffer, Snapshot snapshot, HeapTuple heapTuple,
@@ -163,7 +141,7 @@ extern void heap_get_latest_tid(Relation relation, Snapshot snapshot,
 extern void setLastTid(const ItemPointer tid);
 
 extern BulkInsertState GetBulkInsertState(void);
-extern void FreeBulkInsertState(BulkInsertState);
+extern void FreeBulkInsertState(BulkInsertState bistate);
 extern void ReleaseBulkInsertStatePin(BulkInsertState bistate);
 
 extern void heap_insert(Relation relation, HeapTuple tup, CommandId cid,
@@ -172,17 +150,18 @@ extern void heap_multi_insert(Relation relation, HeapTuple *tuples, int ntuples,
 				  CommandId cid, int options, BulkInsertState bistate);
 extern HTSU_Result heap_delete(Relation relation, ItemPointer tid,
 			CommandId cid, Snapshot crosscheck, bool wait,
-			HeapUpdateFailureData *hufd, bool changingPart);
-extern void heap_finish_speculative(Relation relation, HeapTuple tuple);
-extern void heap_abort_speculative(Relation relation, HeapTuple tuple);
+			struct HeapUpdateFailureData *hufd, bool changingPart);
+extern void heap_finish_speculative(Relation relation, ItemPointer tid);
+extern void heap_abort_speculative(Relation relation, ItemPointer tid);
 extern HTSU_Result heap_update(Relation relation, ItemPointer otid,
 			HeapTuple newtup,
 			CommandId cid, Snapshot crosscheck, bool wait,
-			HeapUpdateFailureData *hufd, LockTupleMode *lockmode);
-extern HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tuple,
+			struct HeapUpdateFailureData *hufd, LockTupleMode *lockmode);
+extern HTSU_Result heap_lock_tuple(Relation relation, ItemPointer tid,
 				CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
-				bool follow_update,
-				Buffer *buffer, HeapUpdateFailureData *hufd);
+				bool follow_update, HeapTuple tuple,
+				Buffer *buffer, struct HeapUpdateFailureData *hufd);
+
 extern void heap_inplace_update(Relation relation, HeapTuple tuple);
 extern bool heap_freeze_tuple(HeapTupleHeader tuple,
 				  TransactionId relfrozenxid, TransactionId relminmxid,
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index 758a7309961..b34e903d84d 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -27,6 +27,32 @@ extern char *default_table_access_method;
 extern bool synchronize_seqscans;

+struct BulkInsertStateData;
+
+/*
+ * When table_update, table_delete, or table_lock_tuple fail because the target
+ * tuple is already outdated, they fill in this struct to provide information
+ * to the caller about what happened.
+ * ctid is the target's ctid link: it is the same as the target's TID if the
+ * target was deleted, or the location of the replacement tuple if the target
+ * was updated.
+ * xmax is the outdating transaction's XID.  If the caller wants to visit the
+ * replacement tuple, it must check that this matches before believing the
+ * replacement is really a match.
+ * cmax is the outdating command's CID, but only when the failure code is
+ * HeapTupleSelfUpdated (i.e., something in the current transaction outdated
+ * the tuple); otherwise cmax is zero.  (We make this restriction because
+ * HeapTupleHeaderGetCmax doesn't work for tuples outdated in other
+ * transactions.)
+ */
+typedef struct HeapUpdateFailureData
+{
+	ItemPointerData ctid;
+	TransactionId xmax;
+	CommandId	cmax;
+	bool		traversed;
+} HeapUpdateFailureData;
+
 /*
  * API struct for a table AM.  Note this must be allocated in a
  * server-lifetime manner, typically as a static const struct, which then gets
@@ -200,6 +226,51 @@ typedef struct TableAmRoutine
 											 TupleTableSlot *slot,
 											 Snapshot snapshot);
 
+	/* ------------------------------------------------------------------------
+	 * Manipulations of physical tuples.
+	 * ------------------------------------------------------------------------
+	 */
+
+	void		(*tuple_insert) (Relation rel, TupleTableSlot *slot, CommandId cid,
+								 int options, struct BulkInsertStateData *bistate);
+	void		(*tuple_insert_speculative) (Relation rel,
+											 TupleTableSlot *slot,
+											 CommandId cid,
+											 int options,
+											 struct BulkInsertStateData *bistate,
+											 uint32 specToken);
+	void		(*tuple_complete_speculative) (Relation rel,
+											   TupleTableSlot *slot,
+											   uint32 specToken,
+											   bool succeeded);
+	HTSU_Result (*tuple_delete) (Relation rel,
+								 ItemPointer tid,
+								 CommandId cid,
+								 Snapshot snapshot,
+								 Snapshot crosscheck,
+								 bool wait,
+								 HeapUpdateFailureData *hufd,
+								 bool changingPart);
+	HTSU_Result (*tuple_update) (Relation rel,
+								 ItemPointer otid,
+								 TupleTableSlot *slot,
+								 CommandId cid,
+								 Snapshot snapshot,
+								 Snapshot crosscheck,
+								 bool wait,
+								 HeapUpdateFailureData *hufd,
+								 LockTupleMode *lockmode,
+								 bool *update_indexes);
+	HTSU_Result (*tuple_lock) (Relation rel,
+							   ItemPointer tid,
+							   Snapshot snapshot,
+							   TupleTableSlot *slot,
+							   CommandId cid,
+							   LockTupleMode mode,
+							   LockWaitPolicy wait_policy,
+							   uint8 flags,
+							   HeapUpdateFailureData *hufd);
+
 } TableAmRoutine;

@@ -487,6 +558,93 @@ table_tuple_satisfies_snapshot(Relation rel, TupleTableSlot *slot, Snapshot snap
 }

+/* ----------------------------------------------------------------------------
+ *  Functions for manipulations of physical tuples.
+ * ----------------------------------------------------------------------------
+ */
+
+/*
+ * Insert a tuple from a slot into table AM routine
+ */
+static inline void
+table_insert(Relation rel, TupleTableSlot *slot, CommandId cid,
+			 int options, struct BulkInsertStateData *bistate)
+{
+	rel->rd_tableam->tuple_insert(rel, slot, cid, options,
+								  bistate);
+}
+
+static inline void
+table_insert_speculative(Relation rel, TupleTableSlot *slot, CommandId cid,
+						 int options, struct BulkInsertStateData *bistate, uint32 specToken)
+{
+	rel->rd_tableam->tuple_insert_speculative(rel, slot, cid, options,
+											  bistate, specToken);
+}
+
+static inline void
+table_complete_speculative(Relation rel, TupleTableSlot *slot, uint32 specToken,
+						   bool succeeded)
+{
+	return rel->rd_tableam->tuple_complete_speculative(rel, slot, specToken,
+													   succeeded);
+}
+
+/*
+ * Delete a tuple from tid using table AM routine
+ */
+static inline HTSU_Result
+table_delete(Relation rel, ItemPointer tid, CommandId cid,
+			 Snapshot snapshot, Snapshot crosscheck, bool wait,
+			 HeapUpdateFailureData *hufd, bool changingPart)
+{
+	return rel->rd_tableam->tuple_delete(rel, tid, cid,
+										 snapshot, crosscheck,
+										 wait, hufd, changingPart);
+}
+
+/*
+ * update a tuple from tid using table AM routine
+ */
+static inline HTSU_Result
+table_update(Relation rel, ItemPointer otid, TupleTableSlot *slot,
+			 CommandId cid, Snapshot snapshot, Snapshot crosscheck, bool wait,
+			 HeapUpdateFailureData *hufd, LockTupleMode *lockmode,
+			 bool *update_indexes)
+{
+	return rel->rd_tableam->tuple_update(rel, otid, slot,
+										 cid, snapshot, crosscheck,
+										 wait, hufd,
+										 lockmode, update_indexes);
+}
+
+/*
+ * Lock a tuple in the specified mode.
+ */
+static inline HTSU_Result
+table_lock_tuple(Relation rel, ItemPointer tid, Snapshot snapshot,
+				 TupleTableSlot *slot, CommandId cid, LockTupleMode mode,
+				 LockWaitPolicy wait_policy, uint8 flags,
+				 HeapUpdateFailureData *hufd)
+{
+	return rel->rd_tableam->tuple_lock(rel, tid, snapshot, slot,
+									   cid, mode, wait_policy,
+									   flags, hufd);
+}
+
+
+/* ----------------------------------------------------------------------------
+ * Functions to make modifications a bit simpler.
+ * ----------------------------------------------------------------------------
+ */
+
+extern void simple_table_delete(Relation rel, ItemPointer tid,
+					Snapshot snapshot);
+extern void simple_table_update(Relation rel, ItemPointer otid,
+					TupleTableSlot *slot,
+					Snapshot snapshot, bool *update_indexes);
+
+
 /* ----------------------------------------------------------------------------
  * Helper functions to implement parallel scans for block oriented AMs.
  * ----------------------------------------------------------------------------
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 9003f2ce583..ceacd1c6370 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -195,12 +195,7 @@ extern LockTupleMode ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo);
 extern ExecRowMark *ExecFindRowMark(EState *estate, Index rti, bool missing_ok);
 extern ExecAuxRowMark *ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist);
 extern TupleTableSlot *EvalPlanQual(EState *estate, EPQState *epqstate,
-			 Relation relation, Index rti, LockTupleMode lockmode,
-			 ItemPointer tid, TransactionId priorXmax);
-extern bool EvalPlanQualFetch(EState *estate, Relation relation,
-				  LockTupleMode lockmode, LockWaitPolicy wait_policy,
-				  ItemPointer tid, TransactionId priorXmax,
-				  TupleTableSlot *slot);
+			 Relation relation, Index rti, TupleTableSlot *testslot);
 extern void EvalPlanQualInit(EPQState *epqstate, EState *estate,
 				 Plan *subplan, List *auxrowmarks, int epqParam);
 extern void EvalPlanQualSetPlan(EPQState *epqstate,
@@ -569,9 +564,8 @@ extern TupleTableSlot *ExecGetReturningSlot(EState *estate, ResultRelInfo *relIn
  */
 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo, bool speculative);
 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
-extern List *ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
-					  EState *estate, bool noDupErr, bool *specConflict,
-					  List *arbiterIndexes);
+extern List *ExecInsertIndexTuples(TupleTableSlot *slot, EState *estate, bool noDupErr,
+					  bool *specConflict, List *arbiterIndexes);
 extern bool ExecCheckIndexConstraints(TupleTableSlot *slot, EState *estate,
 						  ItemPointer conflictTid, List *arbiterIndexes);
 extern void check_exclusion_constraint(Relation heap, Relation index,
diff --git a/src/include/nodes/lockoptions.h b/src/include/nodes/lockoptions.h
index 8e8ccff43ca..d6b1160ab4b 100644
--- a/src/include/nodes/lockoptions.h
+++ b/src/include/nodes/lockoptions.h
@@ -58,4 +58,9 @@ typedef enum LockTupleMode
 	LockTupleExclusive
 } LockTupleMode;
 
+/* Follow tuples whose update is in progress if lock modes don't conflict  */
+#define TUPLE_LOCK_FLAG_LOCK_UPDATE_IN_PROGRESS	(1 << 0)
+/* Follow update chain and lock lastest version of tuple */
+#define TUPLE_LOCK_FLAG_FIND_LAST_VERSION		(1 << 1)
+
 #endif							/* LOCKOPTIONS_H */
diff --git a/src/include/utils/snapshot.h b/src/include/utils/snapshot.h
index e7ea5cf7b56..b976c13cb53 100644
--- a/src/include/utils/snapshot.h
+++ b/src/include/utils/snapshot.h
@@ -193,6 +193,7 @@ typedef enum
 	HeapTupleInvisible,
 	HeapTupleSelfUpdated,
 	HeapTupleUpdated,
+	HeapTupleDeleted,
 	HeapTupleBeingUpdated,
 	HeapTupleWouldBlock			/* can be returned by heap_tuple_lock */
 } HTSU_Result;
diff --git a/src/test/isolation/expected/partition-key-update-1.out b/src/test/isolation/expected/partition-key-update-1.out
index 37fe6a7b277..a632d7f7bad 100644
--- a/src/test/isolation/expected/partition-key-update-1.out
+++ b/src/test/isolation/expected/partition-key-update-1.out
@@ -15,7 +15,7 @@ step s1u: UPDATE foo SET a=2 WHERE a=1;
 step s2d: DELETE FROM foo WHERE a=1; <waiting ...>
 step s1c: COMMIT;
 step s2d: <... completed>
-error in steps s1c s2d: ERROR:  tuple to be deleted was already moved to another partition due to concurrent update
+error in steps s1c s2d: ERROR:  tuple to be locked was already moved to another partition due to concurrent update
 step s2c: COMMIT;
 
 starting permutation: s1b s2b s2d s1u s2c s1c
-- 
2.21.0.dirty

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 filename="v18-0004-tableam-Add-fetch_row_version.patch"