diff --git a/include/common/tglobal.h b/include/common/tglobal.h
index 2a4ef565dd1c6b6742446adee2daf953665b99e5..30ae6c2adb49a811803d04309f43f3068065269c 100644
--- a/include/common/tglobal.h
+++ b/include/common/tglobal.h
@@ -45,6 +45,8 @@ extern bool    tsEnableSlaveQuery;
 extern bool    tsPrintAuth;
 extern int64_t tsTickPerMin[3];
 
+extern int32_t tsCountAlwaysReturnValue;
+
 // multi-process
 extern int32_t tsMultiProcess;
 extern int32_t tsMnodeShmSize;
@@ -102,7 +104,6 @@ extern int32_t tsMaxStreamComputDelay;
 extern int32_t tsStreamCompStartDelay;
 extern int32_t tsRetryStreamCompDelay;
 extern float   tsStreamComputDelayRatio;  // the delayed computing ration of the whole time window
-extern int32_t tsProjectExecInterval;
 extern int64_t tsMaxRetentWindow;
 
 // build info
diff --git a/source/common/src/tglobal.c b/source/common/src/tglobal.c
index 141ec4f03b76238d6c15695c7ea3a8ea112d9e4b..e77c462e5ae0fe81521f34cbd1475669747e0ee6 100644
--- a/source/common/src/tglobal.c
+++ b/source/common/src/tglobal.c
@@ -109,8 +109,11 @@ int32_t tsCompressColData = -1;
  */
 int32_t tsCompatibleModel = 1;
 
+// count/hyperloglog function always return values in case of all NULL data or Empty data set.
+int32_t tsCountAlwaysReturnValue = 1;
+
 // 10 ms for sliding time, the value will changed in case of time precision changed
-int32_t tsMinSlidingTime = 10;
+int32_t   tsMinSlidingTime = 10;
 
 // the maxinum number of distict query result
 int32_t tsMaxNumOfDistinctResults = 1000 * 10000;
@@ -130,7 +133,6 @@ int32_t tsRetryStreamCompDelay = 10 * 1000;
 // The delayed computing ration. 10% of the whole computing time window by default.
 float tsStreamComputDelayRatio = 0.1f;
 
-int32_t tsProjectExecInterval = 10000;   // every 10sec, the projection will be executed once
 int64_t tsMaxRetentWindow = 24 * 3600L;  // maximum time window tolerance
 
 // the maximum allowed query buffer size during query processing for each data node.
@@ -374,6 +376,7 @@ static int32_t taosAddServerCfg(SConfig *pCfg) {
   if (cfgAddInt32(pCfg, "minSlidingTime", tsMinSlidingTime, 10, 1000000, 0) != 0) return -1;
   if (cfgAddInt32(pCfg, "minIntervalTime", tsMinIntervalTime, 1, 1000000, 0) != 0) return -1;
   if (cfgAddInt32(pCfg, "maxNumOfDistinctRes", tsMaxNumOfDistinctResults, 10 * 10000, 10000 * 10000, 0) != 0) return -1;
+  if (cfgAddInt32(pCfg, "countAlwaysReturnValue", tsCountAlwaysReturnValue, 0, 1, 0) != 0) return -1;
   if (cfgAddInt32(pCfg, "maxStreamCompDelay", tsMaxStreamComputDelay, 10, 1000000000, 0) != 0) return -1;
   if (cfgAddInt32(pCfg, "maxFirstStreamCompDelay", tsStreamCompStartDelay, 1000, 1000000000, 0) != 0) return -1;
   if (cfgAddInt32(pCfg, "retryStreamCompDelay", tsRetryStreamCompDelay, 10, 1000000000, 0) != 0) return -1;
@@ -567,6 +570,7 @@ static int32_t taosSetServerCfg(SConfig *pCfg) {
   tsMinSlidingTime = cfgGetItem(pCfg, "minSlidingTime")->i32;
   tsMinIntervalTime = cfgGetItem(pCfg, "minIntervalTime")->i32;
   tsMaxNumOfDistinctResults = cfgGetItem(pCfg, "maxNumOfDistinctRes")->i32;
+  tsCountAlwaysReturnValue = cfgGetItem(pCfg, "countAlwaysReturnValue")->i32;
   tsMaxStreamComputDelay = cfgGetItem(pCfg, "maxStreamCompDelay")->i32;
   tsStreamCompStartDelay = cfgGetItem(pCfg, "maxFirstStreamCompDelay")->i32;
   tsRetryStreamCompDelay = cfgGetItem(pCfg, "retryStreamCompDelay")->i32;
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 6046450f52f9f87ba767d417d0c0095e75d3d90e..b6369c7952b8af7f36586cca24c24668fec68c15 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -433,7 +433,7 @@ static int32_t translateHLL(SFunctionNode* pFunc, char* pErrBuf, int32_t len) {
                            "The input parameter of HYPERLOGLOG function can only be column");
   }
 
-  pFunc->node.resType = (SDataType){.bytes = tDataTypes[TSDB_DATA_TYPE_UBIGINT].bytes, .type = TSDB_DATA_TYPE_UBIGINT};
+  pFunc->node.resType = (SDataType){.bytes = tDataTypes[TSDB_DATA_TYPE_BIGINT].bytes, .type = TSDB_DATA_TYPE_BIGINT};
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 4cfb3b5252fdb257f1947c86468c963d2510c72e..c6c707a91c61a0efbb766108af8657b04e615cb4 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -14,6 +14,7 @@
  */
 
 #include "builtinsimpl.h"
+#include "tglobal.h"
 #include "cJSON.h"
 #include "function.h"
 #include "querynodes.h"
@@ -356,7 +357,7 @@ bool getCountFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
   return true;
 }
 
-static FORCE_INLINE int32_t getNumofElem(SqlFunctionCtx* pCtx) {
+static FORCE_INLINE int32_t getNumOfElems(SqlFunctionCtx* pCtx) {
   int32_t numOfElem = 0;
 
   /*
@@ -391,11 +392,12 @@ static FORCE_INLINE int32_t getNumofElem(SqlFunctionCtx* pCtx) {
  * count function does not use the pCtx->interResBuf to keep the intermediate buffer
  */
 int32_t countFunction(SqlFunctionCtx* pCtx) {
-  int32_t numOfElem = getNumofElem(pCtx);
-  SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
+  int32_t numOfElem = getNumOfElems(pCtx);
 
+  SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
   SInputColumnInfoData* pInput = &pCtx->input;
-  int32_t type   = pInput->pData[0]->info.type;
+
+  int32_t type = pInput->pData[0]->info.type;
 
   char* buf = GET_ROWCELL_INTERBUF(pResInfo);
   if (IS_NULL_TYPE(type)) {
@@ -406,12 +408,17 @@ int32_t countFunction(SqlFunctionCtx* pCtx) {
     *((int64_t*)buf) += numOfElem;
   }
 
-  SET_VAL(pResInfo, numOfElem, 1);
+  if (tsCountAlwaysReturnValue) {
+    pResInfo->numOfRes = 1;
+  } else {
+    SET_VAL(pResInfo, 1, 1);
+  }
+
   return TSDB_CODE_SUCCESS;
 }
 
 int32_t countInvertFunction(SqlFunctionCtx* pCtx) {
-  int32_t numOfElem = getNumofElem(pCtx);
+  int32_t numOfElem = getNumOfElems(pCtx);
 
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
   char*                buf = GET_ROWCELL_INTERBUF(pResInfo);
@@ -3236,13 +3243,13 @@ static uint64_t hllCountCnt(uint8_t *buckets) {
     z += buckethisto[j];
     z *= 0.5;
   }
+
   z += m * hllSigma(buckethisto[0]/(double)m);
   double E = (double)llroundl(HLL_ALPHA_INF*m*m/z);
 
   return (uint64_t) E;
 }
 
-
 int32_t hllFunction(SqlFunctionCtx *pCtx) {
   SHLLInfo* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
 
@@ -3275,7 +3282,6 @@ int32_t hllFunction(SqlFunctionCtx *pCtx) {
     if (count > oldcount) {
       pInfo->buckets[index] = count;
     }
-
   }
 
   SET_VAL(GET_RES_INFO(pCtx), numOfElems, 1);
@@ -3283,9 +3289,13 @@ int32_t hllFunction(SqlFunctionCtx *pCtx) {
 }
 
 int32_t hllFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
-  SHLLInfo* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  SResultRowEntryInfo *pInfo = GET_RES_INFO(pCtx);
 
-  pInfo->result = hllCountCnt(pInfo->buckets);
+  SHLLInfo* pHllInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  pHllInfo->result = hllCountCnt(pHllInfo->buckets);
+  if (tsCountAlwaysReturnValue && pHllInfo->result == 0) {
+    pInfo->numOfRes = 1;
+  }
 
   return functionFinalize(pCtx, pBlock);
 }