diff --git a/src/common/backend/parser/parse_expr.cpp b/src/common/backend/parser/parse_expr.cpp
index b7b881b98..3d61bdf04 100644
--- a/src/common/backend/parser/parse_expr.cpp
+++ b/src/common/backend/parser/parse_expr.cpp
@@ -4156,8 +4156,13 @@ static Node *transformStartWithWhereClauseColumnRef(ParseState *pstate, ColumnRe
     return NULL;
 }
 
-PlannedStmt* getCursorStreamFromFuncArg(FuncExpr* funcexpr, CursorExpression** ce)
+PlannedStmt* getCursorStreamFromFuncArg(Node* node, CursorExpression** ce)
 {
+    if (!IsA(node, FuncExpr)) {
+        return NULL;
+    }
+
+    FuncExpr* funcexpr = (FuncExpr*)node;
     ListCell* lc = NULL;
     foreach (lc, funcexpr->args) {
         Node* arg = (Node*)lfirst(lc);
diff --git a/src/common/backend/parser/parse_relation.cpp b/src/common/backend/parser/parse_relation.cpp
index f92c68b20..1e7660fe6 100755
--- a/src/common/backend/parser/parse_relation.cpp
+++ b/src/common/backend/parser/parse_relation.cpp
@@ -1792,11 +1792,9 @@ RangeTblEntry* addRangeTableEntryForFunction(
      * create_functionscan_path need cursorDop to determine
      * wheather functionscan smp or not.
      */
-    if (IsA(funcexpr, FuncExpr)) {
-        PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg((FuncExpr*)funcexpr);
-        if (cursorPstmt != NULL && IsA(cursorPstmt->planTree, Stream)) {
-            rte->cursorDop = cursorPstmt->planTree->lefttree->dop;
-        }
+    PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg(funcexpr);
+    if (cursorPstmt != NULL && IsA(cursorPstmt->planTree, Stream)) {
+        rte->cursorDop = cursorPstmt->planTree->lefttree->dop;
     }
 
     eref = makeAlias(alias ? alias->aliasname : funcname, NIL);
diff --git a/src/gausskernel/optimizer/plan/createplan.cpp b/src/gausskernel/optimizer/plan/createplan.cpp
index 26683e746..2e25e066f 100755
--- a/src/gausskernel/optimizer/plan/createplan.cpp
+++ b/src/gausskernel/optimizer/plan/createplan.cpp
@@ -6246,7 +6246,7 @@ static FunctionScan* make_functionscan(List* qptlist, List* qpqual, Index scanre
     node->funccolcollations = funccolcollations;
 
     CursorExpression* ce = NULL;
-    PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg((FuncExpr*)funcexpr, &ce);
+    PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg(funcexpr, &ce);
     if (cursorPstmt == NULL) {
         return node;
     }
diff --git a/src/gausskernel/optimizer/plan/streamplan_utils.cpp b/src/gausskernel/optimizer/plan/streamplan_utils.cpp
index 50ca0f152..3780cf127 100755
--- a/src/gausskernel/optimizer/plan/streamplan_utils.cpp
+++ b/src/gausskernel/optimizer/plan/streamplan_utils.cpp
@@ -1898,7 +1898,7 @@ void finalize_node_id(Plan* result_plan, int* plan_node_id, int* parent_node_id,
                 }
             } break;
             case T_FunctionScan: {
-                PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg((FuncExpr*)((FunctionScan*)result_plan)->funcexpr);
+                PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg(((FunctionScan*)result_plan)->funcexpr);
                 if (cursorPstmt != NULL) {
                     cursorPstmt->planTree->cursor_owner_node_id = result_plan->plan_node_id;
                     set_stream_plan_cursor_walker(cursorPstmt->planTree);
diff --git a/src/gausskernel/process/stream/execStream.cpp b/src/gausskernel/process/stream/execStream.cpp
index 9416ca135..5cec707b7 100755
--- a/src/gausskernel/process/stream/execStream.cpp
+++ b/src/gausskernel/process/stream/execStream.cpp
@@ -971,7 +971,7 @@ static void InitStreamFlow(StreamFlowCtl* ctl)
                 InitStreamFlow(ctl);
             } break;
             case T_FunctionScan: {
-                PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg((FuncExpr*)((FunctionScan*)oldPlan)->funcexpr);
+                PlannedStmt* cursorPstmt = getCursorStreamFromFuncArg(((FunctionScan*)oldPlan)->funcexpr);
                 if (cursorPstmt != NULL) {
                     ctl->plan = cursorPstmt->planTree;
 
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 1b9c1a929..fd8b6b2d3 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -39,6 +39,6 @@ extern bool IsQuerySWCBRewrite(Query *query);
 extern bool IsSWCBRewriteRTE(RangeTblEntry *rte);
 extern Datum GetTypeZeroValue(Form_pg_attribute att_tup);
 typedef Datum (*getTypeZeroValueFunc)(Form_pg_attribute att_tup);
-extern PlannedStmt* getCursorStreamFromFuncArg(FuncExpr* funcexpr, CursorExpression** ce = NULL);
+extern PlannedStmt* getCursorStreamFromFuncArg(Node* node, CursorExpression** ce = NULL);
 
 #endif /* PARSE_EXPR_H */
diff --git a/src/test/regress/expected/hw_datatype_2.out b/src/test/regress/expected/hw_datatype_2.out
index 191bf070c..9ebab0daa 100644
--- a/src/test/regress/expected/hw_datatype_2.out
+++ b/src/test/regress/expected/hw_datatype_2.out
@@ -808,6 +808,12 @@ select least(0.9, 1);
     .9
 (1 row)
 
+select * from greatest(1, 1.1);
+ greatest 
+----------
+      1.1
+(1 row)
+
 create or replace function test_cast(a numeric)
 returns int as
 $$
diff --git a/src/test/regress/sql/hw_datatype_2.sql b/src/test/regress/sql/hw_datatype_2.sql
index e42098c15..241e27d49 100644
--- a/src/test/regress/sql/hw_datatype_2.sql
+++ b/src/test/regress/sql/hw_datatype_2.sql
@@ -319,6 +319,8 @@ select greatest(1.1, 1);
 select least(1, 0.9);
 select least(0.9, 1);
 
+select * from greatest(1, 1.1);
+
 create or replace function test_cast(a numeric)
 returns int as
 $$