refactor(query): add an assert.

source/libs/executor/src/timewindowoperator.c

@@ -1027,9 +1027,10 @@ SResultRowPosition addToOpenWindowList(SResultRowInfo* pResultRowInfo, const SRe
 int64_t* extractTsCol(SSDataBlock* pBlock, const SIntervalAggOperatorInfo* pInfo) {
   TSKEY* tsCols = NULL;
 
-  if (pBlock->pDataBlock != NULL) {
+  if (pBlock->pDataBlock != NULL && pBlock->info.dataLoad == 1) {
     SColumnInfoData* pColDataInfo = taosArrayGet(pBlock->pDataBlock, pInfo->primaryTsIndex);
     tsCols = (int64_t*)pColDataInfo->pData;
+    ASSERT(tsCols[0] != 0);
 
     // no data in primary ts
     if (tsCols[0] == 0 && tsCols[pBlock->info.rows - 1] == 0) {