[TD-2293]<enhance>: improve projection query performance for super table.

src/client/src/tscSQLParser.c

@@ -5311,9 +5311,10 @@ int32_t parseLimitClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t clauseIn
 
     if (tscOrderedProjectionQueryOnSTable(pQueryInfo, 0)) {
       /*
-       * the limitation/offset value should be removed during retrieve data from virtual node,
-       * since the global order are done in client side, so the limitation should also
-       * be done at the client side.
+       * the offset value should be removed during retrieve data from virtual node, since the
+       * global order are done in client side, so the offset is applied at the client side
+       * However, note that the maximum allowed number of result for each table should be less
+       * than or equal to the value of limit.
        */
       if (pQueryInfo->limit.limit > 0) {
         pQueryInfo->limit.limit = -1;

src/query/inc/qExecutor.h

@@ -190,6 +190,7 @@ typedef struct SQueryRuntimeEnv {
   bool                 groupbyNormalCol; // denote if this is a groupby normal column query
   bool                 hasTagResults;    // if there are tag values in final result or not
   bool                 timeWindowInterpo;// if the time window start/end required interpolation
+  bool                 queryWindowIdentical; // all query time windows are identical for all tables in one group
   int32_t              interBufSize;     // intermediate buffer sizse
   int32_t              prevGroupId;      // previous executed group id
   SDiskbasedResultBuf* pResultBuf;       // query result buffer based on blocked-wised disk file
@@ -217,7 +218,8 @@ typedef struct SQInfo {
   STableGroupInfo  tableGroupInfo;       // table <tid, last_key> list  SArray<STableKeyInfo>
   STableGroupInfo  tableqinfoGroupInfo;  // this is a group array list, including SArray<STableQueryInfo*> structure
   SQueryRuntimeEnv runtimeEnv;
-  SArray*          arrTableIdInfo;
+//  SArray*          arrTableIdInfo;
+  SHashObj*        arrTableIdInfo;
   int32_t          groupIndex;
 
   /*

src/query/src/qUtil.c

@@ -83,8 +83,6 @@ void resetTimeWindowInfo(SQueryRuntimeEnv *pRuntimeEnv, SWindowResInfo *pWindowR
     return;
   }
 
-//  assert(pWindowResInfo->size == 1);
-
   for (int32_t i = 0; i < pWindowResInfo->size; ++i) {
     SResultRow *pWindowRes = pWindowResInfo->pResult[i];
     clearResultRow(pRuntimeEnv, pWindowRes, pWindowResInfo->type);

src/util/src/hash.c

@@ -151,8 +151,9 @@ static void pushfrontNodeInEntryList(SHashEntry *pEntry, SHashNode *pNode);
  */
 
 SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool update, SHashLockTypeE type) {
-  if (capacity == 0 || fn == NULL) {
-    return NULL;
+  assert(fn != NULL);
+  if (capacity == 0) {
+    capacity = 4;
   }
 
   SHashObj *pHashObj = (SHashObj *)calloc(1, sizeof(SHashObj));