diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 38c022fc6f20e2a55efa076009382228fd437938..cfd94479cb435f957b2c67511c7e775ab1fbf4db 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2677,7 +2677,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
   {
     .name = "csum",
     .type = FUNCTION_TYPE_CSUM,
-    .classification = FUNC_MGT_INDEFINITE_ROWS_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_TIMELINE_FUNC |
+    .classification = FUNC_MGT_INDEFINITE_ROWS_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_TIMELINE_FUNC | FUNC_MGT_IMPLICIT_TS_FUNC |
                       FUNC_MGT_FORBID_STREAM_FUNC | FUNC_MGT_CUMULATIVE_FUNC | FUNC_MGT_KEEP_ORDER_FUNC,
     .translateFunc = translateCsum,
     .getEnvFunc   = getCsumFuncEnv,
@@ -2690,7 +2690,8 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
   {
     .name = "mavg",
     .type = FUNCTION_TYPE_MAVG,
-    .classification = FUNC_MGT_INDEFINITE_ROWS_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_TIMELINE_FUNC | FUNC_MGT_FORBID_STREAM_FUNC,
+    .classification = FUNC_MGT_INDEFINITE_ROWS_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_TIMELINE_FUNC | FUNC_MGT_IMPLICIT_TS_FUNC |
+                      FUNC_MGT_FORBID_STREAM_FUNC,
     .translateFunc = translateMavg,
     .getEnvFunc   = getMavgFuncEnv,
     .initFunc     = mavgFunctionSetup,
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 60befbfba85c41c10dfff854cb12363e77f5aaf2..f23333a6d8737fde4e331cb8513b92e01485f1d4 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -48,6 +48,9 @@ typedef struct SSumRes {
     double   dsum;
   };
   int16_t type;
+  int64_t prevTs; // used for csum only
+  bool    isPrevTsSet; //used for csum only
+
 } SSumRes;
 
 typedef struct SAvgRes {
@@ -207,6 +210,8 @@ typedef enum {
 typedef struct SMavgInfo {
   int32_t pos;
   double  sum;
+  int64_t prevTs;
+  bool    isPrevTsSet;
   int32_t numOfPoints;
   bool    pointsMeet;
   double  points[];
@@ -5008,6 +5013,7 @@ int32_t csumFunction(SqlFunctionCtx* pCtx) {
   SSumRes*             pSumRes = GET_ROWCELL_INTERBUF(pResInfo);
 
   SInputColumnInfoData* pInput = &pCtx->input;
+  TSKEY*                tsList = (int64_t*)pInput->pPTS->pData;
 
   SColumnInfoData* pInputCol = pInput->pData[0];
   SColumnInfoData* pOutput = (SColumnInfoData*)pCtx->pOutput;
@@ -5016,6 +5022,13 @@ int32_t csumFunction(SqlFunctionCtx* pCtx) {
   int32_t type = pInputCol->info.type;
   int32_t startOffset = pCtx->offset;
   for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
+    if (pSumRes->isPrevTsSet == true && tsList[i] == pSumRes->prevTs) {
+      return TSDB_CODE_FUNC_DUP_TIMESTAMP;
+    } else {
+      pSumRes->prevTs = tsList[i];
+    }
+    pSumRes->isPrevTsSet = true;
+
     int32_t pos = startOffset + numOfElems;
     if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
       // colDataAppendNULL(pOutput, i);
@@ -5053,7 +5066,8 @@ int32_t csumFunction(SqlFunctionCtx* pCtx) {
     numOfElems++;
   }
 
-  return numOfElems;
+  pResInfo->numOfRes = numOfElems;
+  return TSDB_CODE_SUCCESS;
 }
 
 bool getMavgFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
@@ -5069,6 +5083,8 @@ bool mavgFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResultInfo) {
   SMavgInfo* pInfo = GET_ROWCELL_INTERBUF(pResultInfo);
   pInfo->pos = 0;
   pInfo->sum = 0;
+  pInfo->prevTs = -1;
+  pInfo->isPrevTsSet = false;
   pInfo->numOfPoints = pCtx->param[1].param.i;
   if (pInfo->numOfPoints < 1 || pInfo->numOfPoints > MAVG_MAX_POINTS_NUM) {
     return false;
@@ -5083,6 +5099,7 @@ int32_t mavgFunction(SqlFunctionCtx* pCtx) {
   SMavgInfo*           pInfo = GET_ROWCELL_INTERBUF(pResInfo);
 
   SInputColumnInfoData* pInput = &pCtx->input;
+  TSKEY*                tsList = (int64_t*)pInput->pPTS->pData;
 
   SColumnInfoData* pInputCol = pInput->pData[0];
   SColumnInfoData* pTsOutput = pCtx->pTsOutput;
@@ -5092,6 +5109,13 @@ int32_t mavgFunction(SqlFunctionCtx* pCtx) {
   int32_t type = pInputCol->info.type;
   int32_t startOffset = pCtx->offset;
   for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
+    if (pInfo->isPrevTsSet == true && tsList[i] == pInfo->prevTs) {
+      return TSDB_CODE_FUNC_DUP_TIMESTAMP;
+    } else {
+      pInfo->prevTs = tsList[i];
+    }
+    pInfo->isPrevTsSet = true;
+
     int32_t pos = startOffset + numOfElems;
     if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
       // colDataAppendNULL(pOutput, i);
@@ -5136,7 +5160,8 @@ int32_t mavgFunction(SqlFunctionCtx* pCtx) {
     }
   }
 
-  return numOfElems;
+  pResInfo->numOfRes = numOfElems;
+  return TSDB_CODE_SUCCESS;
 }
 
 static SSampleInfo* getSampleOutputInfo(SqlFunctionCtx* pCtx) {