*** a/src/backend/executor/nodeLockRows.c
--- b/src/backend/executor/nodeLockRows.c
***************
*** 39,44 **** TupleTableSlot *				/* return: a tuple or NULL */
--- 39,45 ----
  ExecLockRows(LockRowsState *node)
  {
  	TupleTableSlot *slot;
+ 	Plan	   *plan;
  	EState	   *estate;
  	PlanState  *outerPlan;
  	bool		epq_needed;
***************
*** 47,52 **** ExecLockRows(LockRowsState *node)
--- 48,54 ----
  	/*
  	 * get information from the node
  	 */
+ 	plan = node->ps.plan;
  	estate = node->ps.state;
  	outerPlan = outerPlanState(node);
  
***************
*** 214,219 **** lnext:
--- 216,225 ----
  					ereport(ERROR,
  							(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
  							 errmsg("could not serialize access due to concurrent update")));
+ 				if (((LockRows *) plan)->ordering)
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_TRANSACTION_ROLLBACK),
+ 							 errmsg("tuple to be locked was changed due to concurrent update")));
  				if (ItemPointerEquals(&hufd.ctid, &tuple.t_self))
  				{
  					/* Tuple was deleted, so don't return it */
*** a/src/backend/nodes/copyfuncs.c
--- b/src/backend/nodes/copyfuncs.c
***************
*** 967,972 **** _copyLockRows(const LockRows *from)
--- 967,973 ----
  	/*
  	 * copy remainder of node
  	 */
+ 	COPY_SCALAR_FIELD(ordering);
  	COPY_NODE_FIELD(rowMarks);
  	COPY_SCALAR_FIELD(epqParam);
  
*** a/src/backend/nodes/outfuncs.c
--- b/src/backend/nodes/outfuncs.c
***************
*** 842,847 **** _outLockRows(StringInfo str, const LockRows *node)
--- 842,848 ----
  
  	_outPlanInfo(str, (const Plan *) node);
  
+ 	WRITE_BOOL_FIELD(ordering);
  	WRITE_NODE_FIELD(rowMarks);
  	WRITE_INT_FIELD(epqParam);
  }
*** a/src/backend/optimizer/plan/createplan.c
--- b/src/backend/optimizer/plan/createplan.c
***************
*** 4801,4807 **** make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
   *	  Build a LockRows plan node
   */
  LockRows *
! make_lockrows(Plan *lefttree, List *rowMarks, int epqParam)
  {
  	LockRows   *node = makeNode(LockRows);
  	Plan	   *plan = &node->plan;
--- 4801,4807 ----
   *	  Build a LockRows plan node
   */
  LockRows *
! make_lockrows(Plan *lefttree, bool ordering, List *rowMarks, int epqParam)
  {
  	LockRows   *node = makeNode(LockRows);
  	Plan	   *plan = &node->plan;
***************
*** 4816,4821 **** make_lockrows(Plan *lefttree, List *rowMarks, int epqParam)
--- 4816,4822 ----
  	plan->lefttree = lefttree;
  	plan->righttree = NULL;
  
+ 	node->ordering = ordering;
  	node->rowMarks = rowMarks;
  	node->epqParam = epqParam;
  
*** a/src/backend/optimizer/plan/planner.c
--- b/src/backend/optimizer/plan/planner.c
***************
*** 2302,2308 **** grouping_planner(PlannerInfo *root, double tuple_fraction)
--- 2302,2311 ----
  	 */
  	if (parse->rowMarks)
  	{
+ 		bool		ordering = parse->sortClause ? true : false;
+ 
  		result_plan = (Plan *) make_lockrows(result_plan,
+ 											 ordering,
  											 root->rowMarks,
  											 SS_assign_special_param(root));
  
*** a/src/include/nodes/plannodes.h
--- b/src/include/nodes/plannodes.h
***************
*** 809,814 **** typedef struct SetOp
--- 809,815 ----
  typedef struct LockRows
  {
  	Plan		plan;
+ 	bool		ordering;		/* do we need to preserve the ordering? */
  	List	   *rowMarks;		/* a list of PlanRowMark's */
  	int			epqParam;		/* ID of Param for EvalPlanQual re-eval */
  } LockRows;
*** a/src/include/optimizer/planmain.h
--- b/src/include/optimizer/planmain.h
***************
*** 74,80 **** extern Group *make_group(PlannerInfo *root, List *tlist, List *qual,
  		   Plan *lefttree);
  extern Plan *materialize_finished_plan(Plan *subplan);
  extern Unique *make_unique(Plan *lefttree, List *distinctList);
! extern LockRows *make_lockrows(Plan *lefttree, List *rowMarks, int epqParam);
  extern Limit *make_limit(Plan *lefttree, Node *limitOffset, Node *limitCount,
  		   int64 offset_est, int64 count_est);
  extern SetOp *make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
--- 74,80 ----
  		   Plan *lefttree);
  extern Plan *materialize_finished_plan(Plan *subplan);
  extern Unique *make_unique(Plan *lefttree, List *distinctList);
! extern LockRows *make_lockrows(Plan *lefttree, bool ordering, List *rowMarks, int epqParam);
  extern Limit *make_limit(Plan *lefttree, Node *limitOffset, Node *limitCount,
  		   int64 offset_est, int64 count_est);
  extern SetOp *make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,