Revert 11470f544e

Discussion: https://postgr.es/m/20230323003003.plgaxjqahjgkuxrk%40awork3.anarazel.de

src/backend/access/heap/heapam_handler.c

@@ -45,12 +45,6 @@
 #include "utils/builtins.h"
 #include "utils/rel.h"
 
-static TM_Result heapam_tuple_lock_internal(Relation relation, ItemPointer tid,
-											Snapshot snapshot, TupleTableSlot *slot,
-											CommandId cid, LockTupleMode mode,
-											LockWaitPolicy wait_policy, uint8 flags,
-											TM_FailureData *tmfd, bool updated);
-
 static void reform_and_rewrite_tuple(HeapTuple tuple,
 									 Relation OldHeap, Relation NewHeap,
 									 Datum *values, bool *isnull, RewriteState rwstate);
@@ -305,46 +299,14 @@ heapam_tuple_complete_speculative(Relation relation, TupleTableSlot *slot,
 static TM_Result
 heapam_tuple_delete(Relation relation, ItemPointer tid, CommandId cid,
 					Snapshot snapshot, Snapshot crosscheck, bool wait,
-					TM_FailureData *tmfd, bool changingPart,
-					LazyTupleTableSlot *lockedSlot)
+					TM_FailureData *tmfd, bool changingPart)
 {
-	TM_Result	result;
-
 	/*
 	 * 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.
 	 */
-	result = heap_delete(relation, tid, cid, crosscheck, wait,
-						 tmfd, changingPart);
-
-	/*
-	 * If the tuple has been concurrently updated, then get the lock on it.
-	 * (Do this if caller asked for tat by providing a 'lockedSlot'.) With the
-	 * lock held retry of delete should succeed even if there are more
-	 * concurrent update attempts.
-	 */
-	if (result == TM_Updated && lockedSlot)
-	{
-		TupleTableSlot *evalSlot;
-
-		Assert(wait);
-
-		evalSlot = LAZY_TTS_EVAL(lockedSlot);
-		result = heapam_tuple_lock_internal(relation, tid, snapshot,
-											evalSlot, cid, LockTupleExclusive,
-											LockWaitBlock,
-											TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
-											tmfd, true);
-
-		if (result == TM_Ok)
-		{
-			tmfd->traversed = true;
-			return TM_Updated;
-		}
-	}
-
-	return result;
+	return heap_delete(relation, tid, cid, crosscheck, wait, tmfd, changingPart);
 }
 
 
@@ -352,8 +314,7 @@ static TM_Result
 heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
 					CommandId cid, Snapshot snapshot, Snapshot crosscheck,
 					bool wait, TM_FailureData *tmfd,
-					LockTupleMode *lockmode, TU_UpdateIndexes *update_indexes,
-					LazyTupleTableSlot *lockedSlot)
+					LockTupleMode *lockmode, TU_UpdateIndexes *update_indexes)
 {
 	bool		shouldFree = true;
 	HeapTuple	tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
@@ -391,32 +352,6 @@ heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
 	if (shouldFree)
 		pfree(tuple);
 
-	/*
-	 * If the tuple has been concurrently updated, then get the lock on it.
-	 * (Do this if caller asked for tat by providing a 'lockedSlot'.) With the
-	 * lock held retry of update should succeed even if there are more
-	 * concurrent update attempts.
-	 */
-	if (result == TM_Updated && lockedSlot)
-	{
-		TupleTableSlot *evalSlot;
-
-		Assert(wait);
-
-		evalSlot = LAZY_TTS_EVAL(lockedSlot);
-		result = heapam_tuple_lock_internal(relation, otid, snapshot,
-											evalSlot, cid, *lockmode,
-											LockWaitBlock,
-											TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
-											tmfd, true);
-
-		if (result == TM_Ok)
-		{
-			tmfd->traversed = true;
-			return TM_Updated;
-		}
-	}
-
 	return result;
 }
 
@@ -425,26 +360,10 @@ heapam_tuple_lock(Relation relation, ItemPointer tid, Snapshot snapshot,
 				  TupleTableSlot *slot, CommandId cid, LockTupleMode mode,
 				  LockWaitPolicy wait_policy, uint8 flags,
 				  TM_FailureData *tmfd)
-{
-	return heapam_tuple_lock_internal(relation, tid, snapshot, slot, cid,
-									  mode, wait_policy, flags, tmfd, false);
-}
-
-/*
- * This routine does the work for heapam_tuple_lock(), but also support
- * `updated` argument to re-use the work done by heapam_tuple_update() or
- * heapam_tuple_delete() on figuring out that tuple was concurrently updated.
- */
-static TM_Result
-heapam_tuple_lock_internal(Relation relation, ItemPointer tid,
-						   Snapshot snapshot, TupleTableSlot *slot,
-						   CommandId cid, LockTupleMode mode,
-						   LockWaitPolicy wait_policy, uint8 flags,
-						   TM_FailureData *tmfd, bool updated)
 {
 	BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
 	TM_Result	result;
-	Buffer		buffer = InvalidBuffer;
+	Buffer		buffer;
 	HeapTuple	tuple = &bslot->base.tupdata;
 	bool		follow_updates;
 
@@ -455,26 +374,16 @@ heapam_tuple_lock_internal(Relation relation, ItemPointer tid,
 
 tuple_lock_retry:
 	tuple->t_self = *tid;
-	if (!updated)
-		result = heap_lock_tuple(relation, tuple, cid, mode, wait_policy,
-								 follow_updates, &buffer, tmfd);
-	else
-		result = TM_Updated;
+	result = heap_lock_tuple(relation, tuple, cid, mode, wait_policy,
+							 follow_updates, &buffer, tmfd);
 
 	if (result == TM_Updated &&
 		(flags & TUPLE_LOCK_FLAG_FIND_LAST_VERSION))
 	{
-		if (!updated)
-		{
-			/* Should not encounter speculative tuple on recheck */
-			Assert(!HeapTupleHeaderIsSpeculative(tuple->t_data));
+		/* Should not encounter speculative tuple on recheck */
+		Assert(!HeapTupleHeaderIsSpeculative(tuple->t_data));
 
-			ReleaseBuffer(buffer);
-		}
-		else
-		{
-			updated = false;
-		}
+		ReleaseBuffer(buffer);
 
 		if (!ItemPointerEquals(&tmfd->ctid, &tuple->t_self))
 		{

src/backend/access/table/tableam.c

@@ -306,8 +306,7 @@ simple_table_tuple_delete(Relation rel, ItemPointer tid, Snapshot snapshot)
 								GetCurrentCommandId(true),
 								snapshot, InvalidSnapshot,
 								true /* wait for commit */ ,
-								&tmfd, false /* changingPart */ ,
-								NULL);
+								&tmfd, false /* changingPart */ );
 
 	switch (result)
 	{
@@ -356,8 +355,7 @@ simple_table_tuple_update(Relation rel, ItemPointer otid,
 								GetCurrentCommandId(true),
 								snapshot, InvalidSnapshot,
 								true /* wait for commit */ ,
-								&tmfd, &lockmode, update_indexes,
-								NULL);
+								&tmfd, &lockmode, update_indexes);
 
 	switch (result)
 	{

src/backend/executor/nodeModifyTable.c

@@ -1324,62 +1324,26 @@ ExecDeletePrologue(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
 	return true;
 }
 
-/*
- * The implementation for LazyTupleTableSlot wrapper for EPQ slot to be passed
- * to table_tuple_update()/table_tuple_delete().
- */
-typedef struct
-{
-	EPQState   *epqstate;
-	ResultRelInfo *resultRelInfo;
-} GetEPQSlotArg;
-
-static TupleTableSlot *
-GetEPQSlot(void *arg)
-{
-	GetEPQSlotArg *slotArg = (GetEPQSlotArg *) arg;
-
-	return EvalPlanQualSlot(slotArg->epqstate,
-							slotArg->resultRelInfo->ri_RelationDesc,
-							slotArg->resultRelInfo->ri_RangeTableIndex);
-}
-
 /*
  * ExecDeleteAct -- subroutine for ExecDelete
  *
  * Actually delete the tuple from a plain table.
  *
- * If the 'lockUpdated' flag is set and the target tuple is updated, then
- * the latest version gets locked and fetched into the EPQ slot.
- *
  * Caller is in charge of doing EvalPlanQual as necessary
  */
 static TM_Result
 ExecDeleteAct(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-			  ItemPointer tupleid, bool changingPart, bool lockUpdated)
+			  ItemPointer tupleid, bool changingPart)
 {
 	EState	   *estate = context->estate;
-	GetEPQSlotArg slotArg = {context->epqstate, resultRelInfo};
-	LazyTupleTableSlot lazyEPQSlot,
-			   *lazyEPQSlotPtr;
 
-	if (lockUpdated)
-	{
-		MAKE_LAZY_TTS(&lazyEPQSlot, GetEPQSlot, &slotArg);
-		lazyEPQSlotPtr = &lazyEPQSlot;
-	}
-	else
-	{
-		lazyEPQSlotPtr = NULL;
-	}
 	return table_tuple_delete(resultRelInfo->ri_RelationDesc, tupleid,
 							  estate->es_output_cid,
 							  estate->es_snapshot,
 							  estate->es_crosscheck_snapshot,
 							  true /* wait for commit */ ,
 							  &context->tmfd,
-							  changingPart,
-							  lazyEPQSlotPtr);
+							  changingPart);
 }
 
 /*
@@ -1524,8 +1488,7 @@ ExecDelete(ModifyTableContext *context,
 		 * transaction-snapshot mode transactions.
 		 */
 ldelete:
-		result = ExecDeleteAct(context, resultRelInfo, tupleid, changingPart,
-							   !IsolationUsesXactSnapshot());
+		result = ExecDeleteAct(context, resultRelInfo, tupleid, changingPart);
 
 		switch (result)
 		{
@@ -1578,49 +1541,103 @@ ldelete:
 								 errmsg("could not serialize access due to concurrent update")));
 
 					/*
-					 * ExecDeleteAct() has already locked the old tuple for
-					 * us. Now we need to copy it to the right slot.
+					 * Already know that we're going to need to do EPQ, so
+					 * fetch tuple directly into the right slot.
 					 */
 					EvalPlanQualBegin(context->epqstate);
 					inputslot = EvalPlanQualSlot(context->epqstate, resultRelationDesc,
 												 resultRelInfo->ri_RangeTableIndex);
 
-					/*
-					 * Save locked table for further processing for RETURNING
-					 * clause.
-					 */
-					if (processReturning &&
-						resultRelInfo->ri_projectReturning &&
-						!resultRelInfo->ri_FdwRoutine)
+					result = table_tuple_lock(resultRelationDesc, tupleid,
+											  estate->es_snapshot,
+											  inputslot, estate->es_output_cid,
+											  LockTupleExclusive, LockWaitBlock,
+											  TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
+											  &context->tmfd);
+
+					switch (result)
 					{
-						TupleTableSlot *returningSlot;
+						case TM_Ok:
+							Assert(context->tmfd.traversed);
 
-						returningSlot = ExecGetReturningSlot(estate,
-															 resultRelInfo);
-						ExecCopySlot(returningSlot, inputslot);
-						ExecMaterializeSlot(returningSlot);
-					}
+							/*
+							 * Save locked tuple for further processing of
+							 * RETURNING clause.
+							 */
+							if (processReturning &&
+								resultRelInfo->ri_projectReturning &&
+								!resultRelInfo->ri_FdwRoutine)
+							{
+								TupleTableSlot *returningSlot;
+
+								returningSlot = ExecGetReturningSlot(estate, resultRelInfo);
+								ExecCopySlot(returningSlot, inputslot);
+								ExecMaterializeSlot(returningSlot);
+							}
+
+							epqslot = EvalPlanQual(context->epqstate,
+												   resultRelationDesc,
+												   resultRelInfo->ri_RangeTableIndex,
+												   inputslot);
+							if (TupIsNull(epqslot))
+								/* Tuple not passing quals anymore, exiting... */
+								return NULL;
+
+							/*
+							 * If requested, skip delete and pass back the
+							 * updated row.
+							 */
+							if (epqreturnslot)
+							{
+								*epqreturnslot = epqslot;
+								return NULL;
+							}
+							else
+								goto ldelete;
 
-					Assert(context->tmfd.traversed);
-					epqslot = EvalPlanQual(context->epqstate,
-										   resultRelationDesc,
-										   resultRelInfo->ri_RangeTableIndex,
-										   inputslot);
-					if (TupIsNull(epqslot))
-						/* Tuple not passing quals anymore, exiting... */
-						return NULL;
+						case TM_SelfModified:
 
-					/*
-					 * If requested, skip delete and pass back the updated
-					 * row.
-					 */
-					if (epqreturnslot)
-					{
-						*epqreturnslot = epqslot;
-						return NULL;
+							/*
+							 * This can be reached when following an update
+							 * chain from a tuple updated by another session,
+							 * reaching a tuple that was already updated in
+							 * this transaction. If previously updated by this
+							 * command, ignore the delete, otherwise error
+							 * out.
+							 *
+							 * See also TM_SelfModified response to
+							 * table_tuple_delete() above.
+							 */
+							if (context->tmfd.cmax != estate->es_output_cid)
+								ereport(ERROR,
+										(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
+										 errmsg("tuple to be deleted was already modified by an operation triggered by the current command"),
+										 errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
+							return NULL;
+
+						case TM_Deleted:
+							/* tuple already deleted; nothing to do */
+							return NULL;
+
+						default:
+
+							/*
+							 * TM_Invisible should be impossible because we're
+							 * waiting for updated row versions, and would
+							 * already have errored out if the first version
+							 * is invisible.
+							 *
+							 * TM_Updated should be impossible, because we're
+							 * locking the latest version via
+							 * TUPLE_LOCK_FLAG_FIND_LAST_VERSION.
+							 */
+							elog(ERROR, "unexpected table_tuple_lock status: %u",
+								 result);
+							return NULL;
 					}
-					else
-						goto ldelete;
+
+					Assert(false);
+					break;
 				}
 
 			case TM_Deleted:
@@ -1965,15 +1982,12 @@ ExecUpdatePrepareSlot(ResultRelInfo *resultRelInfo,
 static TM_Result
 ExecUpdateAct(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
 			  ItemPointer tupleid, HeapTuple oldtuple, TupleTableSlot *slot,
-			  bool canSetTag, bool lockUpdated, UpdateContext *updateCxt)
+			  bool canSetTag, UpdateContext *updateCxt)
 {
 	EState	   *estate = context->estate;
 	Relation	resultRelationDesc = resultRelInfo->ri_RelationDesc;
 	bool		partition_constraint_failed;
 	TM_Result	result;
-	GetEPQSlotArg slotArg = {context->epqstate, resultRelInfo};
-	LazyTupleTableSlot lazyEPQSlot,
-			   *lazyEPQSlotPtr;
 
 	updateCxt->crossPartUpdate = false;
 
@@ -2099,23 +2113,13 @@ lreplace:
 	 * for referential integrity updates in transaction-snapshot mode
 	 * transactions.
 	 */
-	if (lockUpdated)
-	{
-		MAKE_LAZY_TTS(&lazyEPQSlot, GetEPQSlot, &slotArg);
-		lazyEPQSlotPtr = &lazyEPQSlot;
-	}
-	else
-	{
-		lazyEPQSlotPtr = NULL;
-	}
 	result = table_tuple_update(resultRelationDesc, tupleid, slot,
 								estate->es_output_cid,
 								estate->es_snapshot,
 								estate->es_crosscheck_snapshot,
 								true /* wait for commit */ ,
 								&context->tmfd, &updateCxt->lockmode,
-								&updateCxt->updateIndexes,
-								lazyEPQSlotPtr);
+								&updateCxt->updateIndexes);
 	if (result == TM_Ok)
 		updateCxt->updated = true;
 
@@ -2269,7 +2273,7 @@ ExecCrossPartitionUpdateForeignKey(ModifyTableContext *context,
 static TupleTableSlot *
 ExecUpdate(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
 		   ItemPointer tupleid, HeapTuple oldtuple, TupleTableSlot *slot,
-		   bool canSetTag, bool locked)
+		   bool canSetTag)
 {
 	EState	   *estate = context->estate;
 	Relation	resultRelationDesc = resultRelInfo->ri_RelationDesc;
@@ -2331,8 +2335,7 @@ ExecUpdate(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
 		 */
 redo_act:
 		result = ExecUpdateAct(context, resultRelInfo, tupleid, oldtuple, slot,
-							   canSetTag, !IsolationUsesXactSnapshot(),
-							   &updateCxt);
+							   canSetTag, &updateCxt);
 
 		/*
 		 * If ExecUpdateAct reports that a cross-partition update was done,
@@ -2391,39 +2394,81 @@ redo_act:
 						ereport(ERROR,
 								(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
 								 errmsg("could not serialize access due to concurrent update")));
-					Assert(!locked);
 
 					/*
-					 * ExecUpdateAct() has already locked the old tuple for
-					 * us. Now we need to copy it to the right slot.
+					 * Already know that we're going to need to do EPQ, so
+					 * fetch tuple directly into the right slot.
 					 */
 					inputslot = EvalPlanQualSlot(context->epqstate, resultRelationDesc,
 												 resultRelInfo->ri_RangeTableIndex);
 
-					/* Make sure ri_oldTupleSlot is initialized. */
-					if (unlikely(!resultRelInfo->ri_projectNewInfoValid))
-						ExecInitUpdateProjection(context->mtstate,
-												 resultRelInfo);
+					result = table_tuple_lock(resultRelationDesc, tupleid,
+											  estate->es_snapshot,
+											  inputslot, estate->es_output_cid,
+											  updateCxt.lockmode, LockWaitBlock,
+											  TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
+											  &context->tmfd);
+
+					switch (result)
+					{
+						case TM_Ok:
+							Assert(context->tmfd.traversed);
+
+							/* Make sure ri_oldTupleSlot is initialized. */
+							if (unlikely(!resultRelInfo->ri_projectNewInfoValid))
+								ExecInitUpdateProjection(context->mtstate,
+														 resultRelInfo);
 
-					/*
-					 * Save the locked tuple for further calculation of the
-					 * new tuple.
-					 */
-					oldSlot = resultRelInfo->ri_oldTupleSlot;
-					ExecCopySlot(oldSlot, inputslot);
-					ExecMaterializeSlot(oldSlot);
-					Assert(context->tmfd.traversed);
-
-					epqslot = EvalPlanQual(context->epqstate,
-										   resultRelationDesc,
-										   resultRelInfo->ri_RangeTableIndex,
-										   inputslot);
-					if (TupIsNull(epqslot))
-						/* Tuple not passing quals anymore, exiting... */
-						return NULL;
-					slot = ExecGetUpdateNewTuple(resultRelInfo,
-												 epqslot, oldSlot);
-					goto redo_act;
+							/*
+							 * Save the locked tuple for further calculation
+							 * of the new tuple.
+							 */
+							oldSlot = resultRelInfo->ri_oldTupleSlot;
+							ExecCopySlot(oldSlot, inputslot);
+							ExecMaterializeSlot(oldSlot);
+
+							epqslot = EvalPlanQual(context->epqstate,
+												   resultRelationDesc,
+												   resultRelInfo->ri_RangeTableIndex,
+												   inputslot);
+							if (TupIsNull(epqslot))
+								/* Tuple not passing quals anymore, exiting... */
+								return NULL;
+
+							slot = ExecGetUpdateNewTuple(resultRelInfo,
+														 epqslot, oldSlot);
+							goto redo_act;
+
+						case TM_Deleted:
+							/* tuple already deleted; nothing to do */
+							return NULL;
+
+						case TM_SelfModified:
+
+							/*
+							 * This can be reached when following an update
+							 * chain from a tuple updated by another session,
+							 * reaching a tuple that was already updated in
+							 * this transaction. If previously modified by
+							 * this command, ignore the redundant update,
+							 * otherwise error out.
+							 *
+							 * See also TM_SelfModified response to
+							 * table_tuple_update() above.
+							 */
+							if (context->tmfd.cmax != estate->es_output_cid)
+								ereport(ERROR,
+										(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
+										 errmsg("tuple to be updated was already modified by an operation triggered by the current command"),
+										 errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
+							return NULL;
+
+						default:
+							/* see table_tuple_lock call in ExecDelete() */
+							elog(ERROR, "unexpected table_tuple_lock status: %u",
+								 result);
+							return NULL;
+					}
 				}
 
 				break;
@@ -2665,7 +2710,7 @@ ExecOnConflictUpdate(ModifyTableContext *context,
 	*returning = ExecUpdate(context, resultRelInfo,
 							conflictTid, NULL,
 							resultRelInfo->ri_onConflict->oc_ProjSlot,
-							canSetTag, true);
+							canSetTag);
 
 	/*
 	 * Clear out existing tuple, as there might not be another conflict among
@@ -2868,7 +2913,7 @@ lmerge_matched:
 					break;		/* concurrent update/delete */
 				}
 				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, false, false, &updateCxt);
+									   newslot, false, &updateCxt);
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2886,8 +2931,7 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid,
-									   false, false);
+				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3793,7 +3837,7 @@ ExecModifyTable(PlanState *pstate)
 
 				/* Now apply the update. */
 				slot = ExecUpdate(&context, resultRelInfo, tupleid, oldtuple,
-								  slot, node->canSetTag, false);
+								  slot, node->canSetTag);
 				break;
 
 			case CMD_DELETE:

src/include/access/tableam.h

@@ -530,8 +530,7 @@ typedef struct TableAmRoutine
 								 Snapshot crosscheck,
 								 bool wait,
 								 TM_FailureData *tmfd,
-								 bool changingPart,
-								 LazyTupleTableSlot *lockedSlot);
+								 bool changingPart);
 
 	/* see table_tuple_update() for reference about parameters */
 	TM_Result	(*tuple_update) (Relation rel,
@@ -543,8 +542,7 @@ typedef struct TableAmRoutine
 								 bool wait,
 								 TM_FailureData *tmfd,
 								 LockTupleMode *lockmode,
-								 TU_UpdateIndexes *update_indexes,
-								 LazyTupleTableSlot *lockedSlot);
+								 TU_UpdateIndexes *update_indexes);
 
 	/* see table_tuple_lock() for reference about parameters */
 	TM_Result	(*tuple_lock) (Relation rel,
@@ -1459,7 +1457,7 @@ table_multi_insert(Relation rel, TupleTableSlot **slots, int nslots,
 }
 
 /*
- * Delete a tuple (or lock last tuple version if lockedSlot is given).
+ * Delete a tuple.
  *
  * NB: do not call this directly unless prepared to deal with
  * concurrent-update conditions.  Use simple_table_tuple_delete instead.
@@ -1475,8 +1473,6 @@ table_multi_insert(Relation rel, TupleTableSlot **slots, int nslots,
  *	tmfd - filled in failure cases (see below)
  *	changingPart - true iff the tuple is being moved to another partition
  *		table due to an update of the partition key. Otherwise, false.
- *	lockedSlot - lazy slot to save the locked tuple if should lock the last
- *		row version during the concurrent update. NULL if not needed.
  *
  * Normal, successful return value is TM_Ok, which means we did actually
  * delete it.  Failure return codes are TM_SelfModified, TM_Updated, and
@@ -1489,17 +1485,15 @@ table_multi_insert(Relation rel, TupleTableSlot **slots, int nslots,
 static inline TM_Result
 table_tuple_delete(Relation rel, ItemPointer tid, CommandId cid,
 				   Snapshot snapshot, Snapshot crosscheck, bool wait,
-				   TM_FailureData *tmfd, bool changingPart,
-				   LazyTupleTableSlot *lockedSlot)
+				   TM_FailureData *tmfd, bool changingPart)
 {
 	return rel->rd_tableam->tuple_delete(rel, tid, cid,
 										 snapshot, crosscheck,
-										 wait, tmfd, changingPart,
-										 lockedSlot);
+										 wait, tmfd, changingPart);
 }
 
 /*
- * Update a tuple (or lock last tuple version if lockedSlot is given).
+ * Update a tuple.
  *
  * NB: do not call this directly unless you are prepared to deal with
  * concurrent-update conditions.  Use simple_table_tuple_update instead.
@@ -1517,9 +1511,7 @@ table_tuple_delete(Relation rel, ItemPointer tid, CommandId cid,
  *	lockmode - filled with lock mode acquired on tuple
  *  update_indexes - in success cases this is set to true if new index entries
  *		are required for this tuple
- * 	lockedSlot - lazy slot to save the locked tuple if should lock the last
- *		row version during the concurrent update. NULL if not needed.
-
+ *
  * Normal, successful return value is TM_Ok, which means we did actually
  * update it.  Failure return codes are TM_SelfModified, TM_Updated, and
  * TM_BeingModified (the last only possible if wait == false).
@@ -1538,14 +1530,12 @@ static inline TM_Result
 table_tuple_update(Relation rel, ItemPointer otid, TupleTableSlot *slot,
 				   CommandId cid, Snapshot snapshot, Snapshot crosscheck,
 				   bool wait, TM_FailureData *tmfd, LockTupleMode *lockmode,
-				   TU_UpdateIndexes *update_indexes,
-				   LazyTupleTableSlot *lockedSlot)
+				   TU_UpdateIndexes *update_indexes)
 {
 	return rel->rd_tableam->tuple_update(rel, otid, slot,
 										 cid, snapshot, crosscheck,
 										 wait, tmfd,
-										 lockmode, update_indexes,
-										 lockedSlot);
+										 lockmode, update_indexes);
 }
 
 /*

src/include/executor/tuptable.h

@@ -300,44 +300,6 @@ typedef struct MinimalTupleTableSlot
 #define TupIsNull(slot) \
 	((slot) == NULL || TTS_EMPTY(slot))
 
-/*----------
- * LazyTupleTableSlot -- a lazy version of TupleTableSlot.
- *
- * Sometimes caller might need to pass to the function a slot, which most
- * likely will reain undemanded.  Preallocating such slot would be a waste of
- * resources in the  majority of cases.  Lazy slot is aimed to resolve this
- * problem.  It is basically a promise to allocate the slot once it's needed.
- * Once callee needs the slot, it could get it using LAZY_TTS_EVAL(lazySlot)
- * macro.
- */
-typedef struct
-{
-	TupleTableSlot *slot;		/* cached slot or NULL if not yet allocated */
-	TupleTableSlot *(*getSlot) (void *arg); /* callback for slot allocation */
-	void	   *getSlotArg;		/* argument for the callback above */
-} LazyTupleTableSlot;
-
-/*
- * A constructor for the lazy slot.
- */
-#define MAKE_LAZY_TTS(lazySlot, callback, arg) \
-	do { \
-		(lazySlot)->slot = NULL; \
-		(lazySlot)->getSlot = callback; \
-		(lazySlot)->getSlotArg = arg; \
-	} while (false)
-
-/*
- * Macro for lazy slot evaluation.  NULL lazy slot evaluates to NULL slot.
- * Cached version is used if present.  Use the callback otherwise.
- */
-#define LAZY_TTS_EVAL(lazySlot) \
-	((lazySlot) ? \
-		((lazySlot)->slot ? \
-			(lazySlot)->slot : \
-			((lazySlot)->slot = (lazySlot)->getSlot((lazySlot)->getSlotArg))) : \
-		NULL)
-
 /* in executor/execTuples.c */
 extern TupleTableSlot *MakeTupleTableSlot(TupleDesc tupleDesc,
 										  const TupleTableSlotOps *tts_ops);

src/tools/pgindent/typedefs.list

@@ -956,7 +956,6 @@ GenerationPointer
 GenericCosts
 GenericXLogState
 GeqoPrivateData
-GetEPQSlotArg
 GetForeignJoinPaths_function
 GetForeignModifyBatchSize_function
 GetForeignPaths_function
@@ -1402,7 +1401,6 @@ LagTracker
 LargeObjectDesc
 LastAttnumInfo
 Latch
-LazyTupleTableSlot
 LerpFunc
 LexDescr
 LexemeEntry