diff --git a/source/libs/function/src/functionMgt.c b/source/libs/function/src/functionMgt.c
index a406b23c59..5dfb94ba6e 100644
--- a/source/libs/function/src/functionMgt.c
+++ b/source/libs/function/src/functionMgt.c
@@ -412,6 +412,13 @@ int32_t createFunction(const char* pName, SNodeList* pParameterList, SFunctionNo
   return code;
 }
 
+static void resetOutputChangedFunc(SFunctionNode *pFunc, const SFunctionNode* pSrcFunc) {
+  if (funcMgtBuiltins[pFunc->funcId].type == FUNCTION_TYPE_LAST_MERGE) {
+    pFunc->node.resType = pSrcFunc->node.resType;
+    return;
+  }
+}
+
 int32_t createFunctionWithSrcFunc(const char* pName, const SFunctionNode* pSrcFunc, SNodeList* pParameterList, SFunctionNode** ppFunc) {
   int32_t code = nodesMakeNode(QUERY_NODE_FUNCTION, (SNode**)ppFunc);
   if (NULL == *ppFunc) {
@@ -430,6 +437,7 @@ int32_t createFunctionWithSrcFunc(const char* pName, const SFunctionNode* pSrcFu
     *ppFunc = NULL;
     return code;
   }
+  resetOutputChangedFunc(*ppFunc, pSrcFunc);
   return code;
 }
 
diff --git a/source/libs/planner/src/planOptimizer.c b/source/libs/planner/src/planOptimizer.c
index 39024731ed..0cc26dfce9 100644
--- a/source/libs/planner/src/planOptimizer.c
+++ b/source/libs/planner/src/planOptimizer.c
@@ -4258,7 +4258,7 @@ typedef struct SLastRowScanOptSetColDataTypeCxt {
   int32_t    code;
 } SLastRowScanOptSetColDataTypeCxt;
 
-static EDealRes lastRowScanOptSetColDataType(SNode* pNode, void* pContext) {
+static EDealRes lastRowScanOptGetColAndSetDataType(SNode* pNode, void* pContext, bool setType) {
   if (QUERY_NODE_COLUMN == nodeType(pNode)) {
     SLastRowScanOptSetColDataTypeCxt* pCxt = pContext;
     if (pCxt->doAgg) {
@@ -4266,12 +4266,12 @@ static EDealRes lastRowScanOptSetColDataType(SNode* pNode, void* pContext) {
       if (TSDB_CODE_SUCCESS != pCxt->code) {
         return DEAL_RES_ERROR;
       }
-      getLastCacheDataType(&(((SColumnNode*)pNode)->node.resType), pCxt->pkBytes);
+      if (setType) getLastCacheDataType(&(((SColumnNode*)pNode)->node.resType), pCxt->pkBytes);
     } else {
       SNode* pCol = NULL;
       FOREACH(pCol, pCxt->pLastCols) {
         if (nodesEqualNode(pCol, pNode)) {
-          getLastCacheDataType(&(((SColumnNode*)pNode)->node.resType), pCxt->pkBytes);
+          if (setType) getLastCacheDataType(&(((SColumnNode*)pNode)->node.resType), pCxt->pkBytes);
           break;
         }
       }
@@ -4281,6 +4281,14 @@ static EDealRes lastRowScanOptSetColDataType(SNode* pNode, void* pContext) {
   return DEAL_RES_CONTINUE;
 }
 
+static EDealRes lastRowScanOptGetLastCols(SNode* pNode, void* pContext) {
+  return lastRowScanOptGetColAndSetDataType(pNode, pContext, false);
+}
+
+static EDealRes lastRowScanOptSetColDataType(SNode* pNode, void* pContext) {
+  return lastRowScanOptGetColAndSetDataType(pNode, pContext, true);
+}
+
 static void lastRowScanOptSetLastTargets(SNodeList* pTargets, SNodeList* pLastCols, SNodeList* pLastRowCols, bool erase, int32_t pkBytes) {
   SNode* pTarget = NULL;
   WHERE_EACH(pTarget, pTargets) {
@@ -4393,7 +4401,7 @@ static int32_t lastRowScanOptimize(SOptimizeContext* pCxt, SLogicSubplan* pLogic
     SNode*         pParamNode = NULL;
     if (FUNCTION_TYPE_LAST == funcType) {
       (void)nodesListErase(pFunc->pParameterList, nodesListGetCell(pFunc->pParameterList, 1));
-      nodesWalkExpr(nodesListGetNode(pFunc->pParameterList, 0), lastRowScanOptSetColDataType, &cxt);
+      nodesWalkExpr(nodesListGetNode(pFunc->pParameterList, 0), lastRowScanOptGetLastCols, &cxt);
       if (TSDB_CODE_SUCCESS != cxt.code) break;
     }
     FOREACH(pParamNode, pFunc->pParameterList) {