diff --git a/src/backend/distributed/executor/multi_executor.c b/src/backend/distributed/executor/multi_executor.c
index c99dd3914..b5a94efa7 100644
--- a/src/backend/distributed/executor/multi_executor.c
+++ b/src/backend/distributed/executor/multi_executor.c
@@ -33,7 +33,7 @@
 
 
 /*
- * Create separate set of scan methods for different executor types.
+ * Define executor methods for the different executor types.
  */
 static CustomExecMethods RealTimeCustomExecMethods = {
 	.CustomName = "RealTimeScan",
@@ -88,8 +88,7 @@ static Relation StubRelation(TupleDesc tupleDescriptor);
 
 
 /*
- * RealTimeCreateScan creates a custom scan node which sets callback functions
- * for real-time executor.
+ * RealTimeCreateScan creates the scan state for real-time executor queries.
  */
 Node *
 RealTimeCreateScan(CustomScan *scan)
@@ -107,8 +106,7 @@ RealTimeCreateScan(CustomScan *scan)
 
 
 /*
- * TaskTrackerCreateScan creates a custom scan node which sets callback functions
- * for task-tracker executor.
+ * TaskTrackerCreateScan creates the scan state for task-tracker executor queries.
  */
 Node *
 TaskTrackerCreateScan(CustomScan *scan)
@@ -126,8 +124,7 @@ TaskTrackerCreateScan(CustomScan *scan)
 
 
 /*
- * RouterCreateScan creates a custom scan node which sets callback functions
- * for router executor depending on the router executor type.
+ * RouterCreateScan creates the scan state for router executor queries.
  */
 Node *
 RouterCreateScan(CustomScan *scan)
@@ -136,6 +133,7 @@ RouterCreateScan(CustomScan *scan)
 	MultiPlan *multiPlan = NULL;
 	Job *workerJob = NULL;
 	List *taskList = NIL;
+	bool isModificationQuery = false;
 
 	scanState->executorType = MULTI_EXECUTOR_ROUTER;
 	scanState->customScanState.ss.ps.type = T_CustomScanState;
@@ -145,10 +143,11 @@ RouterCreateScan(CustomScan *scan)
 	workerJob = multiPlan->workerJob;
 	taskList = workerJob->taskList;
 
+	isModificationQuery = IsModifyMultiPlan(multiPlan);
+
 	/* check if this is a single shard query */
 	if (list_length(taskList) == 1)
 	{
-		bool isModificationQuery = IsModifyMultiPlan(multiPlan);
 		if (isModificationQuery)
 		{
 			scanState->customScanState.methods = &RouterSingleModifyCustomExecMethods;
@@ -160,6 +159,7 @@ RouterCreateScan(CustomScan *scan)
 	}
 	else
 	{
+		Assert(isModificationQuery);
 		scanState->customScanState.methods = &RouterMultiModifyCustomExecMethods;
 	}
 
@@ -168,8 +168,8 @@ RouterCreateScan(CustomScan *scan)
 
 
 /*
- * InvalidCreateScan is only called on an invalid case which we would like to
- * error out. This is the case when a plan is not ready for execution because
+ * DelayedErrorCreateScan is only called on an invalid case which we would like
+ * to error out. This is the case when a plan is not ready for execution because
  * CreateDistributedPlan() couldn't find a plan due to unresolved prepared
  * statement parameters, but didn't error out, because we expect custom plans
  * to come to our rescue. But sql (not plpgsql) functions unfortunately don't
@@ -177,7 +177,7 @@ RouterCreateScan(CustomScan *scan)
  * to do this check and provide a meaningfull error message.
  */
 Node *
-InvalidCreateScan(CustomScan *scan)
+DelayedErrorCreateScan(CustomScan *scan)
 {
 	CitusScanState *scanState = palloc0(sizeof(CitusScanState));
 
@@ -195,29 +195,12 @@ InvalidCreateScan(CustomScan *scan)
 
 
 /*
- * CitusSelectBeginScan just checks if the given custom scan node is a proper
- * Citus scan node.
+ * CitusSelectBeginScan is a placeholder function for BeginCustomScan callback.
  */
 void
 CitusSelectBeginScan(CustomScanState *node, EState *estate, int eflags)
 {
-	ValidateCitusScanState(node);
-}
-
-
-/*
- * ValidateCitusScanState checks if the given scan nodes contains a valid multi plan.
- */
-void
-ValidateCitusScanState(CustomScanState *node)
-{
-	CitusScanState *scanState = (CitusScanState *) node;
-	MultiPlan *multiPlan = scanState->multiPlan;
-
-	Assert(IsA(scanState, CustomScanState));
-
-	/* ensure plan is executable */
-	VerifyMultiPlanValidity(multiPlan);
+	/* just a placeholder function */
 }
 
 
@@ -246,7 +229,7 @@ RealTimeExecScan(CustomScanState *node)
 		scanState->finishedRemoteScan = true;
 	}
 
-	resultSlot = ReadNextTuple(scanState);
+	resultSlot = ReturnTupleFromTuplestore(scanState);
 
 	return resultSlot;
 }
@@ -281,6 +264,7 @@ LoadTuplesIntoTupleStore(CitusScanState *citusScanState, Job *workerJob)
 {
 	CustomScanState customScanState = citusScanState->customScanState;
 	List *workerTaskList = workerJob->taskList;
+	List *copyOptions = NIL;
 	EState *executorState = NULL;
 	MemoryContext executorTupleContext = NULL;
 	ExprContext *executorExpressionContext = NULL;
@@ -308,23 +292,22 @@ LoadTuplesIntoTupleStore(CitusScanState *citusScanState, Job *workerJob)
 	citusScanState->tuplestorestate =
 		tuplestore_begin_heap(randomAccess, interTransactions, work_mem);
 
+	if (BinaryMasterCopyFormat)
+	{
+		DefElem *copyOption = makeDefElem("format", (Node *) makeString("binary"));
+		copyOptions = lappend(copyOptions, copyOption);
+	}
+
 	foreach(workerTaskCell, workerTaskList)
 	{
 		Task *workerTask = (Task *) lfirst(workerTaskCell);
 		StringInfo jobDirectoryName = NULL;
 		StringInfo taskFilename = NULL;
-		List *copyOptions = NIL;
 		CopyState copyState = NULL;
 
 		jobDirectoryName = MasterJobDirectoryName(workerTask->jobId);
 		taskFilename = TaskFilename(jobDirectoryName, workerTask->taskId);
 
-		if (BinaryMasterCopyFormat)
-		{
-			DefElem *copyOption = makeDefElem("format", (Node *) makeString("binary"));
-			copyOptions = lappend(copyOptions, copyOption);
-		}
-
 		copyState = BeginCopyFrom(stubRelation, taskFilename->data, false, NULL,
 								  copyOptions);
 
@@ -373,12 +356,12 @@ StubRelation(TupleDesc tupleDescriptor)
 
 
 /*
- * ReadNextTuple reads the next tuple from the tuple store of the given Citus
- * scan node and returns it. It returns null if all tuples are read from the
- * tuple store.
+ * ReturnTupleFromTuplestore reads the next tuple from the tuple store of the
+ * given Citus scan node and returns it. It returns null if all tuples are read
+ * from the tuple store.
  */
 TupleTableSlot *
-ReadNextTuple(CitusScanState *scanState)
+ReturnTupleFromTuplestore(CitusScanState *scanState)
 {
 	Tuplestorestate *tupleStore = scanState->tuplestorestate;
 	TupleTableSlot *resultSlot = NULL;
@@ -430,7 +413,7 @@ TaskTrackerExecScan(CustomScanState *node)
 		scanState->finishedRemoteScan = true;
 	}
 
-	resultSlot = ReadNextTuple(scanState);
+	resultSlot = ReturnTupleFromTuplestore(scanState);
 
 	return resultSlot;
 }
diff --git a/src/backend/distributed/executor/multi_router_executor.c b/src/backend/distributed/executor/multi_router_executor.c
index 7e0ba55e2..9a26090f8 100644
--- a/src/backend/distributed/executor/multi_router_executor.c
+++ b/src/backend/distributed/executor/multi_router_executor.c
@@ -417,8 +417,6 @@ CitusModifyBeginScan(CustomScanState *node, EState *estate, int eflags)
 	Job *workerJob = multiPlan->workerJob;
 	List *taskList = workerJob->taskList;
 
-	ValidateCitusScanState(node);
-
 	/*
 	 * If we are executing a prepared statement, then we may not yet have obtained
 	 * the metadata locks in this transaction. To prevent a concurrent shard copy,
@@ -458,7 +456,7 @@ RouterSingleModifyExecScan(CustomScanState *node)
 		scanState->finishedRemoteScan = true;
 	}
 
-	resultSlot = ReadNextTuple(scanState);
+	resultSlot = ReturnTupleFromTuplestore(scanState);
 
 	return resultSlot;
 }
@@ -508,7 +506,7 @@ RouterMultiModifyExecScan(CustomScanState *node)
 		scanState->finishedRemoteScan = true;
 	}
 
-	resultSlot = ReadNextTuple(scanState);
+	resultSlot = ReturnTupleFromTuplestore(scanState);
 
 	return resultSlot;
 }
@@ -539,7 +537,7 @@ RouterSelectExecScan(CustomScanState *node)
 		scanState->finishedRemoteScan = true;
 	}
 
-	resultSlot = ReadNextTuple(scanState);
+	resultSlot = ReturnTupleFromTuplestore(scanState);
 
 	return resultSlot;
 }
diff --git a/src/backend/distributed/planner/multi_planner.c b/src/backend/distributed/planner/multi_planner.c
index 6a9d29c38..172978b40 100644
--- a/src/backend/distributed/planner/multi_planner.c
+++ b/src/backend/distributed/planner/multi_planner.c
@@ -50,7 +50,7 @@ static CustomScanMethods RouterCustomScanMethods = {
 
 static CustomScanMethods InvalidCustomScanMethods = {
 	"Citus Invalid",
-	InvalidCreateScan
+	DelayedErrorCreateScan
 };
 
 
@@ -143,11 +143,11 @@ multi_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
 
 
 /*
- * IsModifyQuery returns true if the query performs modifications, false
+ * IsModifyCommand returns true if the query performs modifications, false
  * otherwise.
  */
 bool
-IsModifyQuery(Query *query)
+IsModifyCommand(Query *query)
 {
 	CmdType commandType = query->commandType;
 
@@ -218,7 +218,7 @@ CreateDistributedPlan(PlannedStmt *localPlan, Query *originalQuery, Query *query
 		hasUnresolvedParams = true;
 	}
 
-	if (IsModifyQuery(query))
+	if (IsModifyCommand(query))
 	{
 		/* modifications are always routed through the same planner/executor */
 		distributedPlan = CreateModifyPlan(originalQuery, query, restrictionContext);
diff --git a/src/include/distributed/multi_executor.h b/src/include/distributed/multi_executor.h
index ea048dace..e3b53a327 100644
--- a/src/include/distributed/multi_executor.h
+++ b/src/include/distributed/multi_executor.h
@@ -38,7 +38,7 @@ typedef struct CitusScanState
 extern Node * RealTimeCreateScan(CustomScan *scan);
 extern Node * TaskTrackerCreateScan(CustomScan *scan);
 extern Node * RouterCreateScan(CustomScan *scan);
-extern Node * InvalidCreateScan(CustomScan *scan);
+extern Node * DelayedErrorCreateScan(CustomScan *scan);
 extern void CitusSelectBeginScan(CustomScanState *node, EState *estate, int eflags);
 extern TupleTableSlot * RealTimeExecScan(CustomScanState *node);
 extern TupleTableSlot * TaskTrackerExecScan(CustomScanState *node);
@@ -46,8 +46,7 @@ extern void CitusEndScan(CustomScanState *node);
 extern void CitusReScan(CustomScanState *node);
 extern void CitusExplainScan(CustomScanState *node, List *ancestors, struct
 							 ExplainState *es);
-extern void ValidateCitusScanState(CustomScanState *node);
-extern TupleTableSlot * ReadNextTuple(CitusScanState *scanState);
+extern TupleTableSlot * ReturnTupleFromTuplestore(CitusScanState *scanState);
 
 
 #endif /* MULTI_EXECUTOR_H */
diff --git a/src/include/distributed/multi_planner.h b/src/include/distributed/multi_planner.h
index e21fe3b39..ed9dae4ea 100644
--- a/src/include/distributed/multi_planner.h
+++ b/src/include/distributed/multi_planner.h
@@ -55,7 +55,7 @@ struct MultiPlan;
 extern struct MultiPlan * GetMultiPlan(CustomScan *node);
 extern void multi_relation_restriction_hook(PlannerInfo *root, RelOptInfo *relOptInfo,
 											Index index, RangeTblEntry *rte);
-extern bool IsModifyQuery(Query *query);
+extern bool IsModifyCommand(Query *query);
 extern bool IsModifyMultiPlan(struct MultiPlan *multiPlan);
 extern void VerifyMultiPlanValidity(struct MultiPlan *multiPlan);
 extern RangeTblEntry * RemoteScanRangeTableEntry(List *columnNameList);