diff --git a/source/libs/function/inc/builtinsimpl.h b/source/libs/function/inc/builtinsimpl.h
index db92740fff260f07dbc438166b7d04682bbea136..40393a4eabb83c37bc555da0eddf35e0d5c2233e 100644
--- a/source/libs/function/inc/builtinsimpl.h
+++ b/source/libs/function/inc/builtinsimpl.h
@@ -40,6 +40,11 @@ bool getMinmaxFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv);
 int32_t minFunction(SqlFunctionCtx* pCtx);
 int32_t maxFunction(SqlFunctionCtx *pCtx);
 
+bool getAvgFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv);
+bool avgFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo);
+int32_t avgFunction(SqlFunctionCtx* pCtx);
+int32_t avgFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock, int32_t slotId);
+
 bool getStddevFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv);
 bool stddevFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo);
 int32_t stddevFunction(SqlFunctionCtx* pCtx);
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 3da5dc3289e246d6202c984bbc64f40eecde2832..70087ee46bf3b2f49a8876372c1df75c8cdb582a 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -104,7 +104,7 @@ static int32_t translateCount(SFunctionNode* pFunc, char* pErrBuf, int32_t len)
   if (1 != LIST_LENGTH(pFunc->pParameterList)) {
     return invaildFuncParaNumErrMsg(pErrBuf, len, pFunc->functionName);
   }
-  pFunc->node.resType = (SDataType){.bytes = sizeof(int64_t), .type = TSDB_DATA_TYPE_BIGINT};
+  pFunc->node.resType = (SDataType){.bytes = tDataTypes[TSDB_DATA_TYPE_BIGINT].bytes, .type = TSDB_DATA_TYPE_BIGINT};
   return TSDB_CODE_SUCCESS;
 }
 
@@ -479,6 +479,16 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .processFunc  = stddevFunction,
     .finalizeFunc = stddevFinalize
   },
+  {
+    .name = "avg",
+    .type = FUNCTION_TYPE_AVG,
+    .classification = FUNC_MGT_AGG_FUNC,
+    .translateFunc = translateInNumOutDou,
+    .getEnvFunc   = getAvgFuncEnv,
+    .initFunc     = avgFunctionSetup,
+    .processFunc  = avgFunction,
+    .finalizeFunc = avgFinalize
+  },
   {
     .name = "percentile",
     .type = FUNCTION_TYPE_PERCENTILE,
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 3dc2e62e92e4b8e28d4178032b4aaed81d050a8a..63af2fb97225014483a328b9e700eaf58ef20683 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -20,6 +20,59 @@
 #include "tdatablock.h"
 #include "tpercentile.h"
 
+typedef struct SSumRes {
+  union {
+    int64_t  isum;
+    uint64_t usum;
+    double   dsum;
+  };
+} SSumRes;
+
+typedef struct SAvgRes {
+  double  result;
+  SSumRes sum;
+  int64_t count;
+} SAvgRes;
+
+typedef struct STopBotResItem {
+  SVariant v;
+  uint64_t uid;        // it is a table uid, used to extract tag data during building of the final result for the tag data
+  struct {
+   int32_t pageId;
+   int32_t offset;
+  } tuplePos;          // tuple data of this chosen row
+} STopBotResItem;
+
+typedef struct STopBotRes {
+  int32_t         pageId;
+//  int32_t   num;
+  STopBotResItem *pItems;
+} STopBotRes;
+
+typedef struct SStddevRes {
+  double  result;
+  int64_t count;
+  union  {double  quadraticDSum; int64_t quadraticISum;};
+  union  {double  dsum; int64_t isum;};
+} SStddevRes;
+
+typedef struct SPercentileInfo {
+  double      result;
+  tMemBucket *pMemBucket;
+  int32_t     stage;
+  double      minval;
+  double      maxval;
+  int64_t     numOfElems;
+} SPercentileInfo;
+
+typedef struct SDiffInfo {
+  bool  hasPrev;
+  bool  includeNull;
+  bool  ignoreNegative;
+  bool  firstOutput;
+  union { int64_t i64; double d64;} prev;
+} SDiffInfo;
+
 #define SET_VAL(_info, numOfElem, res)  \
   do {                                  \
     if ((numOfElem) <= 0) {             \
@@ -28,13 +81,50 @@
     (_info)->numOfRes = (res);          \
   } while (0)
 
-typedef struct SSumRes {
-  union {
-    int64_t  isum;
-    uint64_t usum;
-    double   dsum;
-  };
-} SSumRes;
+#define GET_TS_LIST(x)    ((TSKEY*)((x)->ptsList))
+#define GET_TS_DATA(x, y) (GET_TS_LIST(x)[(y)])
+
+#define DO_UPDATE_TAG_COLUMNS_WITHOUT_TS(ctx)                      \
+  do {                                                             \
+    for (int32_t _i = 0; _i < (ctx)->tagInfo.numOfTagCols; ++_i) { \
+      SqlFunctionCtx *__ctx = (ctx)->tagInfo.pTagCtxList[_i];      \
+      __ctx->fpSet.process(__ctx);                                 \
+    }                                                              \
+  } while (0);
+
+#define DO_UPDATE_SUBSID_RES(ctx, ts)                                 \
+  do {                                                                \
+    for (int32_t _i = 0; _i < (ctx)->subsidiaryRes.numOfCols; ++_i) { \
+      SqlFunctionCtx *__ctx = (ctx)->subsidiaryRes.pCtx[_i];          \
+      if (__ctx->functionId == FUNCTION_TS_DUMMY) {                   \
+        __ctx->tag.i = (ts);                                          \
+        __ctx->tag.nType = TSDB_DATA_TYPE_BIGINT;                     \
+      }                                                               \
+      __ctx->fpSet.process(__ctx);                                    \
+    }                                                                 \
+  } while (0)
+
+#define UPDATE_DATA(ctx, left, right, num, sign, _ts) \
+  do {                                                \
+    if (((left) < (right)) ^ (sign)) {                \
+      (left) = (right);                               \
+      DO_UPDATE_SUBSID_RES(ctx, _ts);                 \
+      (num) += 1;                                     \
+    }                                                 \
+  } while (0)
+
+#define LOOPCHECK_N(val, _col, ctx, _t, _nrow, _start, sign, num)        \
+  do {                                                                   \
+    _t *d = (_t *)((_col)->pData);                                       \
+    for (int32_t i = (_start); i < (_nrow) + (_start); ++i) {            \
+      if (((_col)->hasNull) && colDataIsNull_f((_col)->nullbitmap, i)) { \
+        continue;                                                        \
+      }                                                                  \
+      TSKEY ts = (ctx)->ptsList != NULL ? GET_TS_DATA(ctx, i) : 0;       \
+      UPDATE_DATA(ctx, val, d[i], num, sign, ts);                        \
+    }                                                                    \
+  } while (0)
+
 
 bool functionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo) {
   if (pResultInfo->initialized) {
@@ -135,7 +225,7 @@ int32_t sumFunction(SqlFunctionCtx *pCtx) {
   int32_t type = pInput->pData[0]->info.type;
 
   SSumRes* pSumRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
-  
+
   if (pInput->colDataAggIsSet) {
     numOfElem = pInput->numOfRows - pAgg->numOfNull;
     ASSERT(numOfElem >= 0);
@@ -190,6 +280,145 @@ bool getSumFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
   return true;
 }
 
+bool getAvgFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
+  pEnv->calcMemSize = sizeof(double);
+  return true;
+}
+
+bool avgFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo) {
+  if (!functionSetup(pCtx, pResultInfo)) {
+    return false;
+  }
+
+  SAvgRes* pRes = GET_ROWCELL_INTERBUF(pResultInfo);
+  memset(pRes, 0, sizeof(SAvgRes));
+  return true;
+}
+
+int32_t avgFunction(SqlFunctionCtx* pCtx) {
+  int32_t numOfElem = 0;
+
+  // Only the pre-computing information loaded and actual data does not loaded
+  SInputColumnInfoData* pInput = &pCtx->input;
+  int32_t               type = pInput->pData[0]->info.type;
+
+  SAvgRes* pAvgRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+
+  // computing based on the true data block
+  SColumnInfoData* pCol = pInput->pData[0];
+
+  int32_t start = pInput->startRowIndex;
+  int32_t numOfRows = pInput->numOfRows;
+
+  switch (type) {
+    case TSDB_DATA_TYPE_TINYINT: {
+        int8_t* plist = (int8_t*)pCol->pData;
+        for (int32_t i = start; i < numOfRows + pInput->startRowIndex; ++i) {
+          if (pCol->hasNull && colDataIsNull_f(pCol->nullbitmap, i)) {
+            continue;
+          }
+
+          numOfElem += 1;
+          pAvgRes->count += 1;
+          pAvgRes->sum.isum += plist[i];
+        }
+
+        break;
+      }
+
+      case TSDB_DATA_TYPE_SMALLINT: {
+      int16_t* plist = (int16_t*)pCol->pData;
+      for (int32_t i = start; i < numOfRows + pInput->startRowIndex; ++i) {
+        if (pCol->hasNull && colDataIsNull_f(pCol->nullbitmap, i)) {
+          continue;
+        }
+
+        numOfElem += 1;
+        pAvgRes->count += 1;
+        pAvgRes->sum.isum += plist[i];
+      }
+      break;
+    }
+
+    case TSDB_DATA_TYPE_INT: {
+      int32_t* plist = (int32_t*)pCol->pData;
+      for (int32_t i = start; i < numOfRows + pInput->startRowIndex; ++i) {
+        if (pCol->hasNull && colDataIsNull_f(pCol->nullbitmap, i)) {
+          continue;
+        }
+
+        numOfElem += 1;
+        pAvgRes->count += 1;
+        pAvgRes->sum.isum += plist[i];
+      }
+
+      break;
+    }
+
+    case TSDB_DATA_TYPE_BIGINT: {
+      int64_t* plist = (int64_t*)pCol->pData;
+      for (int32_t i = start; i < numOfRows + pInput->startRowIndex; ++i) {
+        if (pCol->hasNull && colDataIsNull_f(pCol->nullbitmap, i)) {
+          continue;
+        }
+
+        numOfElem += 1;
+        pAvgRes->count += 1;
+        pAvgRes->sum.isum += plist[i];
+      }
+      break;
+    }
+
+    case TSDB_DATA_TYPE_FLOAT: {
+      float* plist = (float*)pCol->pData;
+      for (int32_t i = start; i < numOfRows + pInput->startRowIndex; ++i) {
+        if (pCol->hasNull && colDataIsNull_f(pCol->nullbitmap, i)) {
+          continue;
+        }
+
+        numOfElem += 1;
+        pAvgRes->count += 1;
+        pAvgRes->sum.dsum += plist[i];
+      }
+      break;
+    }
+
+    case TSDB_DATA_TYPE_DOUBLE: {
+      double* plist = (double*)pCol->pData;
+      for (int32_t i = start; i < numOfRows + pInput->startRowIndex; ++i) {
+        if (pCol->hasNull && colDataIsNull_f(pCol->nullbitmap, i)) {
+          continue;
+        }
+
+        numOfElem += 1;
+        pAvgRes->count += 1;
+        pAvgRes->sum.dsum += plist[i];
+      }
+      break;
+    }
+
+    default:
+      break;
+  }
+
+  // data in the check operation are all null, not output
+  SET_VAL(GET_RES_INFO(pCtx), numOfElem, 1);
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t avgFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock, int32_t slotId) {
+  SInputColumnInfoData* pInput = &pCtx->input;
+  int32_t type = pInput->pData[0]->info.type;
+  SAvgRes* pAvgRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  if (IS_INTEGER_TYPE(type)) {
+    pAvgRes->result = pAvgRes->sum.isum / ((double) pAvgRes->count);
+  } else {
+    pAvgRes->result = pAvgRes->sum.dsum / ((double) pAvgRes->count);
+  }
+
+  return functionFinalize(pCtx, pBlock, slotId);
+}
+
 EFuncDataRequired statisDataRequired(SFunctionNode* pFunc, STimeWindow* pTimeWindow){
   return FUNC_DATA_REQUIRED_STATIS_LOAD;
 }
@@ -292,49 +521,6 @@ bool getMinmaxFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
   return true;
 }
 
-#define GET_TS_LIST(x)    ((TSKEY*)((x)->ptsList))
-#define GET_TS_DATA(x, y) (GET_TS_LIST(x)[(y)])
-
-#define DO_UPDATE_TAG_COLUMNS_WITHOUT_TS(ctx)                      \
-  do {                                                             \
-    for (int32_t _i = 0; _i < (ctx)->tagInfo.numOfTagCols; ++_i) { \
-      SqlFunctionCtx *__ctx = (ctx)->tagInfo.pTagCtxList[_i];      \
-      __ctx->fpSet.process(__ctx);                                 \
-    }                                                              \
-  } while (0);
-
-#define DO_UPDATE_SUBSID_RES(ctx, ts)                                 \
-  do {                                                                \
-    for (int32_t _i = 0; _i < (ctx)->subsidiaryRes.numOfCols; ++_i) { \
-      SqlFunctionCtx *__ctx = (ctx)->subsidiaryRes.pCtx[_i];          \
-      if (__ctx->functionId == FUNCTION_TS_DUMMY) {                   \
-        __ctx->tag.i = (ts);                                          \
-        __ctx->tag.nType = TSDB_DATA_TYPE_BIGINT;                     \
-      }                                                               \
-      __ctx->fpSet.process(__ctx);                                    \
-    }                                                                 \
-  } while (0)
-
-#define UPDATE_DATA(ctx, left, right, num, sign, _ts) \
-  do {                                                \
-    if (((left) < (right)) ^ (sign)) {                \
-      (left) = (right);                               \
-      DO_UPDATE_SUBSID_RES(ctx, _ts);                 \
-      (num) += 1;                                     \
-    }                                                 \
-  } while (0)
-
-#define LOOPCHECK_N(val, _col, ctx, _t, _nrow, _start, sign, num)        \
-  do {                                                                   \
-    _t *d = (_t *)((_col)->pData);                                       \
-    for (int32_t i = (_start); i < (_nrow) + (_start); ++i) {            \
-      if (((_col)->hasNull) && colDataIsNull_f((_col)->nullbitmap, i)) { \
-        continue;                                                        \
-      }                                                                  \
-      TSKEY ts = (ctx)->ptsList != NULL ? GET_TS_DATA(ctx, i) : 0;       \
-      UPDATE_DATA(ctx, val, d[i], num, sign, ts);                        \
-    }                                                                    \
-  } while (0)
 
 int32_t doMinMaxHelper(SqlFunctionCtx *pCtx, int32_t isMinFunc) {
   int32_t numOfElems = 0;
@@ -479,13 +665,6 @@ int32_t maxFunction(SqlFunctionCtx *pCtx) {
   return TSDB_CODE_SUCCESS;
 }
 
-typedef struct SStddevRes {
-  double  result;
-  int64_t count;
-  union  {double  quadraticDSum; int64_t quadraticISum;};
-  union  {double  dsum; int64_t isum;};
-} SStddevRes;
-
 bool getStddevFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
   pEnv->calcMemSize = sizeof(SStddevRes);
   return true;
@@ -588,8 +767,8 @@ int32_t stddevFunction(SqlFunctionCtx* pCtx) {
 
         numOfElem += 1;
         pStddevRes->count += 1;
-        pStddevRes->isum += plist[i];
-        pStddevRes->quadraticISum += plist[i] * plist[i];
+        pStddevRes->dsum += plist[i];
+        pStddevRes->quadraticDSum += plist[i] * plist[i];
       }
       break;
     }
@@ -603,8 +782,8 @@ int32_t stddevFunction(SqlFunctionCtx* pCtx) {
 
         numOfElem += 1;
         pStddevRes->count += 1;
-        pStddevRes->isum += plist[i];
-        pStddevRes->quadraticISum += plist[i] * plist[i];
+        pStddevRes->dsum += plist[i];
+        pStddevRes->quadraticDSum += plist[i] * plist[i];
       }
       break;
     }
@@ -619,21 +798,21 @@ int32_t stddevFunction(SqlFunctionCtx* pCtx) {
 }
 
 int32_t stddevFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock, int32_t slotId) {
+  SInputColumnInfoData* pInput = &pCtx->input;
+  int32_t type = pInput->pData[0]->info.type;
   SStddevRes* pStddevRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
-  double avg = pStddevRes->isum / ((double) pStddevRes->count);
-  pStddevRes->result = sqrt(pStddevRes->quadraticISum/((double)pStddevRes->count) - avg*avg);
+  double avg;
+  if (IS_INTEGER_TYPE(type)) {
+    avg = pStddevRes->isum / ((double) pStddevRes->count);
+    pStddevRes->result = sqrt(pStddevRes->quadraticISum/((double)pStddevRes->count) - avg*avg);
+  } else {
+    avg = pStddevRes->dsum / ((double) pStddevRes->count);
+    pStddevRes->result = sqrt(pStddevRes->quadraticDSum/((double)pStddevRes->count) - avg*avg);
+  }
+
   return functionFinalize(pCtx, pBlock, slotId);
 }
 
-typedef struct SPercentileInfo {
-  double      result;
-  tMemBucket *pMemBucket;
-  int32_t     stage;
-  double      minval;
-  double      maxval;
-  int64_t     numOfElems;
-} SPercentileInfo;
-
 bool getPercentileFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
   pEnv->calcMemSize = sizeof(SPercentileInfo);
   return true;
@@ -928,14 +1107,6 @@ int32_t lastFunction(SqlFunctionCtx *pCtx) {
   return TSDB_CODE_SUCCESS;
 }
 
-typedef struct SDiffInfo {
-  bool  hasPrev;
-  bool  includeNull;
-  bool  ignoreNegative;
-  bool  firstOutput;
-  union { int64_t i64; double d64;} prev;
-} SDiffInfo;
-
 bool getDiffFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
   pEnv->calcMemSize = sizeof(SDiffInfo);
   return true;
@@ -1168,21 +1339,6 @@ int32_t diffFunction(SqlFunctionCtx *pCtx) {
   }
 }
 
-typedef struct STopBotResItem {
-  SVariant v;
-  uint64_t uid;        // it is a table uid, used to extract tag data during building of the final result for the tag data
-  struct {
-   int32_t pageId;
-   int32_t offset;
-  } tuplePos;          // tuple data of this chosen row
-} STopBotResItem;
-
-typedef struct STopBotRes {
-  int32_t         pageId;
-//  int32_t   num;
-  STopBotResItem *pItems;
-} STopBotRes;
-
 bool getTopBotFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
   SValueNode* pkNode = (SValueNode*) nodesListGetNode(pFunc->pParameterList, 1);
   pEnv->calcMemSize = sizeof(STopBotRes) + pkNode->datum.i * sizeof(STopBotResItem);
@@ -1335,4 +1491,4 @@ int32_t topBotFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock, int32_t slotId
   return pEntryInfo->numOfRes;
 
 //  return functionFinalize(pCtx, pBlock, slotId);
-}
\ No newline at end of file
+}