diff --git a/source/libs/function/inc/builtinsimpl.h b/source/libs/function/inc/builtinsimpl.h
index 2f31d57907..1bb30934c6 100644
--- a/source/libs/function/inc/builtinsimpl.h
+++ b/source/libs/function/inc/builtinsimpl.h
@@ -55,7 +55,9 @@ int32_t maxCombine(SqlFunctionCtx* pDestCtx, SqlFunctionCtx* pSourceCtx);
 bool getAvgFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv);
 bool avgFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo);
 int32_t avgFunction(SqlFunctionCtx* pCtx);
+int32_t avgFunctionMerge(SqlFunctionCtx* pCtx);
 int32_t avgFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock);
+int32_t avgPartialFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock);
 int32_t avgInvertFunction(SqlFunctionCtx* pCtx);
 int32_t avgCombine(SqlFunctionCtx* pDestCtx, SqlFunctionCtx* pSourceCtx);
 int32_t getAvgInfoSize();
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index ee47b1aa7f..fe9b4e1c3a 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -51,6 +51,7 @@ typedef struct SAvgRes {
   double  result;
   SSumRes sum;
   int64_t count;
+  int16_t type;  // store the original input type, used in merge function
 } SAvgRes;
 
 typedef struct STuplePos {
@@ -649,6 +650,7 @@ int32_t avgFunction(SqlFunctionCtx* pCtx) {
   int32_t               type = pInput->pData[0]->info.type;
 
   SAvgRes* pAvgRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  pAvgRes->type = type;
 
   // computing based on the true data block
   SColumnInfoData* pCol = pInput->pData[0];
@@ -771,6 +773,38 @@ _avg_over:
   return TSDB_CODE_SUCCESS;
 }
 
+static void avgTransferInfo(SAvgRes* pInput, SAvgRes* pOutput) {
+  int16_t type = pInput->type;
+  if (IS_INTEGER_TYPE(type)) {
+    pOutput->sum.isum += pInput->sum.isum;
+  } else {
+    pOutput->sum.dsum += pInput->sum.dsum;
+  }
+
+  pOutput->count += pInput->count;
+
+  return;
+}
+
+int32_t avgFunctionMerge(SqlFunctionCtx* pCtx) {
+  SInputColumnInfoData* pInput = &pCtx->input;
+  SColumnInfoData*      pCol = pInput->pData[0];
+  ASSERT(pCol->info.type == TSDB_DATA_TYPE_BINARY);
+
+  SAvgRes* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  SAvgRes* pInputInfo;
+
+  int32_t start = pInput->startRowIndex;
+  char*   data = colDataGetData(pCol, start);
+  pInputInfo = (SAvgRes*)varDataVal(data);
+
+  avgTransferInfo(pInputInfo, pInfo);
+
+  SET_VAL(GET_RES_INFO(pCtx), 1, 1);
+
+  return TSDB_CODE_SUCCESS;
+}
+
 #define LIST_AVG_N(sumT, T)                                               \
   do {                                                                    \
     T* plist = (T*)pCol->pData;                                           \
@@ -872,6 +906,24 @@ int32_t avgFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   return functionFinalize(pCtx, pBlock);
 }
 
+int32_t avgPartialFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
+  SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
+  SAvgRes* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  int32_t  resultBytes = getAvgInfoSize();
+  char*    res = taosMemoryCalloc(resultBytes + VARSTR_HEADER_SIZE, sizeof(char));
+
+  memcpy(varDataVal(res), pInfo, resultBytes);
+  varDataSetLen(res, resultBytes);
+
+  int32_t          slotId = pCtx->pExpr->base.resSchema.slotId;
+  SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, slotId);
+
+  colDataAppend(pCol, pBlock->info.rows, res, false);
+
+  taosMemoryFree(res);
+  return pResInfo->numOfRes;
+}
+
 EFuncDataRequired statisDataRequired(SFunctionNode* pFunc, STimeWindow* pTimeWindow) {
   return FUNC_DATA_REQUIRED_STATIS_LOAD;
 }