[TS-1318]<fix>: changed scan operator in real subqueries

src/client/src/tscSubquery.c

@@ -662,6 +662,7 @@ static int32_t tscLaunchRealSubqueries(SSqlObj* pSql) {
       } else {
         filterVgroupTables(pQueryInfo, pTableMetaInfo->pVgroupTables);
       }
+      pQueryInfo->stableQuery = true;
     }
 
     subquerySetState(pNew, &pSql->subState, i, 0);

src/client/src/tscUtil.c

@@ -394,7 +394,7 @@ bool tscIsPointInterpQuery(SQueryInfo* pQueryInfo) {
 }
 
 bool tscNeedTableSeqScan(SQueryInfo* pQueryInfo) {
-  return pQueryInfo->stableQuery && (tscQueryContainsFunction(pQueryInfo, TSDB_FUNC_TWA) || tscQueryContainsFunction(pQueryInfo, TSDB_FUNC_ELAPSED));
+  return pQueryInfo->stableQuery && (tscQueryContainsFunction(pQueryInfo, TSDB_FUNC_TWA) || tscQueryContainsFunction(pQueryInfo, TSDB_FUNC_ELAPSED) || (pQueryInfo->tsBuf != NULL));
 }
 
 bool tscGetPointInterpQuery(SQueryInfo* pQueryInfo) {

src/query/src/qExecutor.c

@@ -4832,7 +4832,7 @@ static int32_t setupQueryHandle(void* tsdb, SQueryRuntimeEnv* pRuntimeEnv, int64
   }
 
   STsdbQueryCond cond = createTsdbQueryCond(pQueryAttr, &pQueryAttr->window);
-  if (pQueryAttr->tsCompQuery || pQueryAttr->pointInterpQuery) {
+  if (pQueryAttr->tsCompQuery || pQueryAttr->pointInterpQuery || pQueryAttr->needTableSeqScan) {
     cond.type = BLOCK_LOAD_TABLE_SEQ_ORDER;    
   }