enh(query): avg function use pre-agg results

source/libs/function/src/builtinsimpl.c

@@ -642,8 +642,8 @@ bool avgFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResultInfo) {
 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;
+  SColumnDataAgg*       pAgg = pInput->pColumnDataAgg[0];
   int32_t               type = pInput->pData[0]->info.type;
 
   SAvgRes* pAvgRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
@@ -660,6 +660,17 @@ int32_t avgFunction(SqlFunctionCtx* pCtx) {
     goto _avg_over;
   }
 
+  if (pInput->colDataAggIsSet) {
+    numOfElem = numOfRows - pAgg->numOfNull;
+    ASSERT(numOfElem >= 0);
+
+    pAvgRes->count += numOfElem;
+    if (IS_INTEGER_TYPE(type)) {
+      pAvgRes->sum.isum += pAgg->sum;
+    } else if (IS_FLOAT_TYPE(type)) {
+      pAvgRes->sum.dsum += GET_DOUBLE_VAL((const char*)&(pAgg->sum));
+    }
+  } else {  // computing based on the true data block
     switch (type) {
       case TSDB_DATA_TYPE_TINYINT: {
         int8_t* plist = (int8_t*)pCol->pData;
@@ -750,6 +761,7 @@ int32_t avgFunction(SqlFunctionCtx* pCtx) {
       default:
         break;
     }
+  }
 
 _avg_over:
   // data in the check operation are all null, not output