diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 5a2e35045018a4780be8dff09c13454a039d4ab7..254c39d37e388b97fe3df38132e3a19e3fdece8c 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -2457,6 +2457,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
   const char* msg10 = "derivative duration should be greater than 1 Second";
   const char* msg11 = "third parameter in derivative should be 0 or 1";
   const char* msg12 = "parameter is out of range [1, 100]";
+  const char* msg13 = "third parameter should be 0 or 1";
 
   switch (functionId) {
     case TSDB_FUNC_COUNT: {
@@ -2790,8 +2791,16 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
     case TSDB_FUNC_PERCT:
     case TSDB_FUNC_APERCT: {
       // 1. valid the number of parameters
-      if (pItem->pNode->Expr.paramList == NULL || taosArrayGetSize(pItem->pNode->Expr.paramList) != 2) {
-        /* no parameters or more than one parameter for function */
+      bool valid = true;
+      if(pItem->pNode->Expr.paramList == NULL) {
+        valid = false;
+      } else if(functionId == TSDB_FUNC_APERCT) {
+        size_t cnt = taosArrayGetSize(pItem->pNode->Expr.paramList);
+        if(cnt != 2 && cnt !=3) valid = false;
+      } else {
+        if (taosArrayGetSize(pItem->pNode->Expr.paramList) != 2) valid = false;
+      }
+      if(!valid) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg2);
       }
 
@@ -2837,16 +2846,14 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
 
       SExprInfo* pExpr = NULL;
       if (functionId == TSDB_FUNC_PERCT || functionId == TSDB_FUNC_APERCT) {
+        // param1 double 
         tVariantDump(pVariant, val, TSDB_DATA_TYPE_DOUBLE, true);
-
         double dp = GET_DOUBLE_VAL(val);
         if (dp < 0 || dp > TOP_BOTTOM_QUERY_LIMIT) {
           return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg5);
         }
-
         getResultDataInfo(pSchema->type, pSchema->bytes, functionId, 0, &resultType, &resultSize, &interResult, 0, false,
             pUdfInfo);
-
         /*
          * sql function transformation
          * for dp = 0, it is actually min,
@@ -2854,9 +2861,22 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
          */
         tscInsertPrimaryTsSourceColumn(pQueryInfo, pTableMetaInfo->pTableMeta->id.uid);
         colIndex += 1;  // the first column is ts
-
         pExpr = tscExprAppend(pQueryInfo, functionId, &index, resultType, resultSize, getNewResColId(pCmd), interResult, false);
         tscExprAddParams(&pExpr->base, val, TSDB_DATA_TYPE_DOUBLE, sizeof(double));
+
+        // param2 int32
+        if (taosArrayGetSize(pItem->pNode->Expr.paramList) == 3) {
+          if (pParamElem[2].pNode != NULL) {
+            pVariant = &pParamElem[2].pNode->value;
+            tVariantDump(pVariant, val, TSDB_DATA_TYPE_INT, true);
+            int32_t algo = GET_INT32_VAL(val);
+            if(algo < 0 || algo >1 ) {
+              return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg13);
+            }
+            tscExprAddParams(&pExpr->base, val, TSDB_DATA_TYPE_INT, sizeof(int32_t));
+          }
+        }
+
       } else {
         tVariantDump(pVariant, val, TSDB_DATA_TYPE_BIGINT, true);
 
diff --git a/src/query/inc/qAggMain.h b/src/query/inc/qAggMain.h
index d4116fbfb2daec9b47c4a891c3c886728e6ca515..37fbcf67bc050336290bf3952a58cdd1cdf44232 100644
--- a/src/query/inc/qAggMain.h
+++ b/src/query/inc/qAggMain.h
@@ -106,6 +106,10 @@ extern "C" {
 #define MAX_INTERVAL_TIME_WINDOW 1000000  // maximum allowed time windows in final results
 #define TOP_BOTTOM_QUERY_LIMIT   100
 
+// apercentile(arg1,agr2,arg3) param arg3 value is below:
+#define ALGO_DEFAULT 0
+#define ALGO_TDIGEST 1
+
 enum {
   MASTER_SCAN   = 0x0u,
   REVERSE_SCAN  = 0x1u,
diff --git a/src/query/src/qAggMain.c b/src/query/src/qAggMain.c
index 81c39d6fc7d66725508738f31382a36f8a05ee1d..8d0ad37472a68d119128ff75f479153a266d7ada 100644
--- a/src/query/src/qAggMain.c
+++ b/src/query/src/qAggMain.c
@@ -2451,7 +2451,7 @@ static bool tdigest_setup(SQLFunctionCtx *pCtx, SResultRowCellInfo *pResultInfo)
   
   // new TDigest
   SAPercentileInfo *pAPerc = getAPerctInfo(pCtx);
-  int compression = 5;
+  int compression = 500;
   if(pAPerc) {
     if(pAPerc->pTDigest == NULL) {
       pAPerc->pTDigest = tdigestNew(compression);
@@ -2486,7 +2486,7 @@ static void tdigest_do(SQLFunctionCtx *pCtx) {
     tdigestAdd(pAPerc->pTDigest, v, w);
   }
 
-  tdigestCompress(pAPerc->pTDigest);
+  //tdigestCompress(pAPerc->pTDigest);
 
   if (!pCtx->hasNull) {
     assert(pCtx->size == notNullElems);
@@ -2519,7 +2519,7 @@ static void tdigest_finalizer(SQLFunctionCtx *pCtx) {
 
   if (pCtx->currentStage == MERGE_STAGE) {
     if (pResInfo->hasResult == DATA_SET_FLAG) {  // check for null
-      double res = tdigestQuantile(pAPerc->pTDigest, q);
+      double res = tdigestQuantile(pAPerc->pTDigest, q/100);
       memcpy(pCtx->pOutput, &res, sizeof(double));
     } else {
       setNull(pCtx->pOutput, pCtx->outputType, pCtx->outputBytes);
@@ -2527,7 +2527,7 @@ static void tdigest_finalizer(SQLFunctionCtx *pCtx) {
     }
   } else {
     if (pAPerc->pTDigest->size > 0) {
-      double res = tdigestQuantile(pAPerc->pTDigest, q);
+      double res = tdigestQuantile(pAPerc->pTDigest, q/100);
       memcpy(pCtx->pOutput, &res, sizeof(double));
     } else {  // no need to free
       setNull(pCtx->pOutput, pCtx->outputType, pCtx->outputBytes);
@@ -2542,10 +2542,18 @@ static void tdigest_finalizer(SQLFunctionCtx *pCtx) {
 }
 
 //////////////////////////////////////////////////////////////////////////////////
+int32_t getAlgo(SQLFunctionCtx * pCtx) {
+  if(pCtx->numOfParams != 2){
+    return ALGO_DEFAULT;
+  }
+  if(pCtx->param[1].nType != TSDB_DATA_TYPE_INT) {
+    return ALGO_DEFAULT;
+  }
+  return (int32_t)pCtx->param[1].i64;
+}
 
-int         algo = 1;
 static bool apercentile_function_setup(SQLFunctionCtx *pCtx, SResultRowCellInfo *pResultInfo) {
-  if (algo == 1) {
+  if (getAlgo(pCtx) == ALGO_TDIGEST) {
     return tdigest_setup(pCtx, pResultInfo);
   }
 
@@ -2561,7 +2569,7 @@ static bool apercentile_function_setup(SQLFunctionCtx *pCtx, SResultRowCellInfo
 }
 
 static void apercentile_function(SQLFunctionCtx *pCtx) {
-  if (algo == 1) {
+  if (getAlgo(pCtx) == ALGO_TDIGEST) {
     tdigest_do(pCtx);
     return;
   }
@@ -2598,7 +2606,7 @@ static void apercentile_function(SQLFunctionCtx *pCtx) {
 }
 
 static void apercentile_func_merge(SQLFunctionCtx *pCtx) {
-  if (algo == 1) {
+  if (getAlgo(pCtx) == ALGO_TDIGEST) {
     tdigest_merge(pCtx);
     return;
   }
@@ -2632,8 +2640,9 @@ static void apercentile_func_merge(SQLFunctionCtx *pCtx) {
   SET_VAL(pCtx, 1, 1);
 }
 
+
 static void apercentile_finalizer(SQLFunctionCtx *pCtx) {
-  if (algo == 1) {
+  if (getAlgo(pCtx) == ALGO_TDIGEST) {
     tdigest_finalizer(pCtx);
     return;
   }