diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index e8038d67cd..faab012f04 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -185,6 +185,19 @@ static int32_t translateApercentile(SFunctionNode* pFunc, char* pErrBuf, int32_t
   if (!IS_NUMERIC_TYPE(para1Type) || !IS_INTEGER_TYPE(para2Type)) {
     return invaildFuncParaTypeErrMsg(pErrBuf, len, pFunc->functionName);
   }
+
+  SNode* pParamNode = nodesListGetNode(pFunc->pParameterList, 1);
+  if (nodeType(pParamNode) != QUERY_NODE_VALUE) {
+    return invaildFuncParaTypeErrMsg(pErrBuf, len, pFunc->functionName);
+  }
+  
+  SValueNode* pValue = (SValueNode*)pParamNode;
+  if (pValue->datum.i < 0 || pValue->datum.i > 100) {
+    return invaildFuncParaValueErrMsg(pErrBuf, len, pFunc->functionName);
+  }
+
+  pValue->notReserved = true;
+  
   if (3 == paraNum) {
     SNode* pPara3 = nodesListGetNode(pFunc->pParameterList, 2);
     if (QUERY_NODE_VALUE != nodeType(pPara3) || !validAperventileAlgo((SValueNode*)pPara3)) {
diff --git a/source/libs/scalar/src/sclfunc.c b/source/libs/scalar/src/sclfunc.c
index 45742189d5..12496eec55 100644
--- a/source/libs/scalar/src/sclfunc.c
+++ b/source/libs/scalar/src/sclfunc.c
@@ -824,7 +824,7 @@ int32_t castFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutp
         }
         //for constant conversion, need to set proper length of pOutput description
         if (len < outputLen) {
-          pOutput->columnData->info.bytes = len;
+          pOutput->columnData->info.bytes = len + VARSTR_HEADER_SIZE;
         }
         break;
       }