[TD-2895] refactor

src/client/src/tscAsync.c

@@ -322,7 +322,7 @@ void tscTableMetaCallBack(void *param, TAOS_RES *res, int code) {
       code = tscGetTableMeta(pSql, pTableMetaInfo);
       assert(code == TSDB_CODE_TSC_ACTION_IN_PROGRESS || code == TSDB_CODE_SUCCESS);
 
-      if (code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {        
+      if (code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
         taosReleaseRef(tscObjRef, pSql->self);
         return;
       }

src/client/src/tscLocalMerge.c

@@ -86,7 +86,6 @@ static void tscInitSqlContext(SSqlCmd *pCmd, SLocalMerger *pReducer, tOrderDescr
     pCtx->outputBytes = pExpr->resBytes;
     pCtx->outputType = pExpr->resType;
 
-    pCtx->startOffset = 0;
     pCtx->size = 1;
     pCtx->hasNull = true;
     pCtx->currentStage = MERGE_STAGE;

src/client/src/tscSQLParser.c

@@ -4737,7 +4737,7 @@ static void setDefaultOrderInfo(SQueryInfo* pQueryInfo) {
 int32_t parseOrderbyClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuerySql, SSchema* pSchema) {
   const char* msg0 = "only support order by primary timestamp";
   const char* msg1 = "invalid column name";
-  const char* msg2 = "only support order by primary timestamp or first tag in groupby clause allowed";
+  const char* msg2 = "order by primary timestamp or first tag in groupby clause allowed";
   const char* msg3 = "invalid column in order by clause, only primary timestamp or first tag in groupby clause allowed";
 
   setDefaultOrderInfo(pQueryInfo);

src/client/tests/cliTest.cpp

@@ -57,7 +57,7 @@ void stmtInsertTest() {
   v.ts = start_ts + 20;
   v.k = 123;
 
-  char* str = "abc";
+  char str[] = "abc";
   uintptr_t len = strlen(str);
 
   v.a = str;
@@ -65,7 +65,7 @@ void stmtInsertTest() {
   params[2].buffer_length = len;
   params[2].buffer = str;
 
-  char* nstr = "999";
+  char nstr[] = "999";
   uintptr_t len1 = strlen(nstr);
 
   v.b = nstr;
@@ -84,18 +84,18 @@ void stmtInsertTest() {
   v.ts = start_ts + 30;
   v.k = 911;
 
-  str = "92";
-  len = strlen(str);
+  char str1[] = "92";
+  len = strlen(str1);
 
   params[2].length = &len;
   params[2].buffer_length = len;
-  params[2].buffer = str;
+  params[2].buffer = str1;
 
-  nstr = "1920";
-  len1 = strlen(nstr);
+  char nstr1[] = "1920";
+  len1 = strlen(nstr1);
 
   params[3].buffer_length = len1;
-  params[3].buffer = nstr;
+  params[3].buffer = nstr1;
   params[3].length = &len1;
 
   taos_stmt_bind_param(stmt, params);
@@ -103,7 +103,7 @@ void stmtInsertTest() {
 
   ret = taos_stmt_execute(stmt);
   if (ret != 0) {
-    printf("%p\n", ret);
+    printf("%d\n", ret);
     printf("\033[31mfailed to execute insert statement.\033[0m\n");
     return;
   }

src/cq/src/cqMain.c

@@ -190,7 +190,7 @@ static void freeSCqContext(void *handle) {
   }
   SCqContext *pContext = handle;
   pthread_mutex_destroy(&pContext->mutex);
-    
+
   taosTmrCleanUp(pContext->tmrCtrl);
   pContext->tmrCtrl = NULL;
   cDebug("vgId:%d, CQ is closed", pContext->vgId);
@@ -256,6 +256,7 @@ void cqStop(void *handle) {
   if (tsEnableStream == 0) {
     return;
   }
+
   SCqContext *pContext = handle;
   cDebug("vgId:%d, stop all CQs", pContext->vgId);
   if (pContext->dbConn == NULL || pContext->master == 0) return;

src/query/inc/qAggMain.h

@@ -84,7 +84,7 @@ extern "C" {
 #define TSDB_FUNCSTATE_SO           0x1u    // single output
 #define TSDB_FUNCSTATE_MO           0x2u    // dynamic number of output, not multinumber of output e.g., TOP/BOTTOM
 #define TSDB_FUNCSTATE_STREAM       0x4u    // function avail for stream
-#define TSDB_FUNCSTATE_STABLE       0x8u    // function avail for metric
+#define TSDB_FUNCSTATE_STABLE       0x8u    // function avail for super table
 #define TSDB_FUNCSTATE_OF           0x10u   // outer forward
 #define TSDB_FUNCSTATE_NEED_TS      0x20u   // timestamp is required during query processing
 #define TSDB_FUNCSTATE_SELECTIVITY  0x40u   // selectivity functions, can exists along with tag columns
@@ -166,9 +166,8 @@ typedef struct SExtTagsInfo {
 
 // sql function runtime context
 typedef struct SQLFunctionCtx {
-  int32_t      startOffset;  // todo remove it
   int32_t      size;      // number of rows
-  void *       pInput;    //
+  void *       pInput;    // input data buffer
   uint32_t     order;     // asc|desc
   int16_t      inputType;
   int16_t      inputBytes;
@@ -184,7 +183,7 @@ typedef struct SQLFunctionCtx {
   uint8_t      currentStage;  // record current running step, default: 0
   int64_t      startTs;       // timestamp range of current query when function is executed on a specific data block
   int32_t      numOfParams;
-  tVariant     param[4];      // input parameter, e.g., top(k, 20), the number of results for top query is kept in param */
+  tVariant     param[4];      // input parameter, e.g., top(k, 20), the number of results for top query is kept in param
   int64_t     *ptsList;       // corresponding timestamp array list
   void        *ptsOutputBuf;  // corresponding output buffer for timestamp of each result, e.g., top/bottom*/
   SQLPreAggVal preAggVals;
@@ -228,7 +227,7 @@ int32_t getResultDataInfo(int32_t dataType, int32_t dataBytes, int32_t functionI
 #define IS_SINGLEOUTPUT(x)        (((x)&TSDB_FUNCSTATE_SO) != 0)
 #define IS_OUTER_FORWARD(x)       (((x)&TSDB_FUNCSTATE_OF) != 0)
 
-/* determine the real data need to calculated the result */
+// determine the real data need to calculated the result
 enum {
   BLK_DATA_NO_NEEDED     = 0x0,
   BLK_DATA_STATIS_NEEDED = 0x1,

src/query/inc/qExecutor.h

@@ -33,6 +33,36 @@ struct SColumnFilterElem;
 typedef bool (*__filter_func_t)(struct SColumnFilterElem* pFilter, const char* val1, const char* val2, int16_t type);
 typedef int32_t (*__block_search_fn_t)(char* data, int32_t num, int64_t key, int32_t order);
 
+#define IS_QUERY_KILLED(_q) ((_q)->code == TSDB_CODE_TSC_QUERY_CANCELLED)
+#define Q_STATUS_EQUAL(p, s)  (((p) & (s)) != 0u)
+#define QUERY_IS_ASC_QUERY(q) (GET_FORWARD_DIRECTION_FACTOR((q)->order.order) == QUERY_ASC_FORWARD_STEP)
+
+#define SET_STABLE_QUERY_OVER(_q) ((_q)->tableIndex = (int32_t)((_q)->tableqinfoGroupInfo.numOfTables))
+#define IS_STASBLE_QUERY_OVER(_q) ((_q)->tableIndex >= (int32_t)((_q)->tableqinfoGroupInfo.numOfTables))
+
+#define GET_TABLEGROUP(q, _index)   ((SArray*) taosArrayGetP((q)->tableqinfoGroupInfo.pGroupList, (_index)))
+
+enum {
+  // when query starts to execute, this status will set
+      QUERY_NOT_COMPLETED = 0x1u,
+
+  /* result output buffer is full, current query is paused.
+   * this status is only exist in group-by clause and diff/add/division/multiply/ query.
+   */
+      QUERY_RESBUF_FULL = 0x2u,
+
+  /* query is over
+   * 1. this status is used in one row result query process, e.g., count/sum/first/last/ avg...etc.
+   * 2. when all data within queried time window, it is also denoted as query_completed
+   */
+      QUERY_COMPLETED = 0x4u,
+
+  /* when the result is not completed return to client, this status will be
+   * usually used in case of interval query with interpolation option
+   */
+      QUERY_OVER = 0x8u,
+};
+
 typedef struct SResultRowPool {
   int32_t elemSize;
   int32_t blockSize;
@@ -66,7 +96,8 @@ typedef struct SResultRow {
 } SResultRow;
 
 typedef struct SGroupResInfo {
-  int32_t rowId;
+  int32_t totalGroup;
+  int32_t currentGroup;
   int32_t index;
   SArray* pRows;      // SArray<SResultRow*>
 } SGroupResInfo;
@@ -112,7 +143,7 @@ typedef struct STableQueryInfo {
   STimeWindow win;
   STSCursor   cur;
   void*       pTable;         // for retrieve the page id list
-  SResultRowInfo windowResInfo;
+  SResultRowInfo resInfo;
 } STableQueryInfo;
 
 typedef struct SQueryCostInfo {
@@ -193,7 +224,7 @@ typedef struct SQueryRuntimeEnv {
   uint16_t*            offset;
   uint16_t             scanFlag;         // denotes reversed scan of data or not
   SFillInfo*           pFillInfo;
-  SResultRowInfo       windowResInfo;
+  SResultRowInfo       resultRowInfo;
 
   SQueryCostInfo       summary;
   void*                pQueryHandle;
@@ -257,4 +288,51 @@ typedef struct SQInfo {
   char*            sql;         // query sql string
 } SQInfo;
 
+typedef struct SQueryParam {
+  char            *sql;
+  char            *tagCond;
+  char            *tbnameCond;
+  char            *prevResult;
+  SArray          *pTableIdList;
+  SSqlFuncMsg    **pExprMsg;
+  SSqlFuncMsg    **pSecExprMsg;
+  SExprInfo       *pExprs;
+  SExprInfo       *pSecExprs;
+
+  SColIndex       *pGroupColIndex;
+  SColumnInfo     *pTagColumnInfo;
+  SSqlGroupbyExpr *pGroupbyExpr;
+} SQueryParam;
+
+void freeParam(SQueryParam *param);
+int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SQueryParam* param);
+int32_t createQueryFuncExprFromMsg(SQueryTableMsg *pQueryMsg, int32_t numOfOutput, SExprInfo **pExprInfo, SSqlFuncMsg **pExprMsg,
+                                   SColumnInfo* pTagCols);
+SSqlGroupbyExpr *createGroupbyExprFromMsg(SQueryTableMsg *pQueryMsg, SColIndex *pColIndex, int32_t *code);
+SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SSqlGroupbyExpr *pGroupbyExpr, SExprInfo *pExprs,
+                        SExprInfo *pSecExprs, STableGroupInfo *pTableGroupInfo, SColumnInfo* pTagCols, bool stableQuery, char* sql);
+int32_t initQInfo(SQueryTableMsg *pQueryMsg, void *tsdb, int32_t vgId, SQInfo *pQInfo, SQueryParam* param, bool isSTable);
+void freeColumnFilterInfo(SColumnFilterInfo* pFilter, int32_t numOfFilters);
+
+bool isQueryKilled(SQInfo *pQInfo);
+int32_t checkForQueryBuf(size_t numOfTables);
+bool doBuildResCheck(SQInfo* pQInfo);
+void setQueryStatus(SQuery *pQuery, int8_t status);
+
+bool onlyQueryTags(SQuery* pQuery);
+void buildTagQueryResult(SQInfo *pQInfo);
+void stableQueryImpl(SQInfo *pQInfo);
+void buildTableBlockDistResult(SQInfo *pQInfo);
+void tableQueryImpl(SQInfo *pQInfo);
+bool isValidQInfo(void *param);
+
+int32_t doDumpQueryResult(SQInfo *pQInfo, char *data);
+
+size_t getResultSize(SQInfo *pQInfo, int64_t *numOfRows);
+void setQueryKilled(SQInfo *pQInfo);
+void queryCostStatis(SQInfo *pQInfo);
+void freeQInfo(SQInfo *pQInfo);
+
+int32_t getMaximumIdleDurationSec();
+
 #endif  // TDENGINE_QUERYEXECUTOR_H

src/query/inc/qUtil.h

@@ -85,4 +85,12 @@ void interResToBinary(SBufferWriter* bw, SArray* pRes, int32_t tagLen);
 SArray* interResFromBinary(const char* data, int32_t len);
 void freeInterResult(void* param);
 
+void    initGroupResInfo(SGroupResInfo* pGroupResInfo, SResultRowInfo* pResultInfo, int32_t offset);
+void    cleanupGroupResInfo(SGroupResInfo* pGroupResInfo);
+bool    hasRemainData(SGroupResInfo* pGroupResInfo);
+bool    incNextGroup(SGroupResInfo* pGroupResInfo);
+int32_t getNumOfTotalRes(SGroupResInfo* pGroupResInfo);
+
+int32_t mergeIntoGroupResult(SGroupResInfo* pGroupResInfo, SQInfo *pQInfo);
+
 #endif  // TDENGINE_QUERYUTIL_H

src/query/src/qAggMain.c

@@ -26,10 +26,12 @@
 #include "qTsbuf.h"
 #include "queryLog.h"
 
-#define GET_INPUT_DATA_LIST(x) (((char *)((x)->pInput)) + ((x)->startOffset) * ((x)->inputBytes))
+//#define GET_INPUT_DATA_LIST(x) (((char *)((x)->pInput)) + ((x)->startOffset) * ((x)->inputBytes))
+#define GET_INPUT_DATA_LIST(x) ((char *)((x)->pInput))
 #define GET_INPUT_DATA(x, y) (GET_INPUT_DATA_LIST(x) + (y) * (x)->inputBytes)
 
-#define GET_TS_LIST(x)    ((TSKEY*)&((x)->ptsList[(x)->startOffset]))
+//#define GET_TS_LIST(x)    ((TSKEY*)&((x)->ptsList[(x)->startOffset]))
+#define GET_TS_LIST(x)    ((TSKEY*)((x)->ptsList))
 #define GET_TS_DATA(x, y) (GET_TS_LIST(x)[(y)])
 
 #define GET_TRUE_DATA_TYPE()                          \
@@ -379,11 +381,7 @@ static bool function_setup(SQLFunctionCtx *pCtx) {
 static void function_finalizer(SQLFunctionCtx *pCtx) {
   SResultRowCellInfo *pResInfo = GET_RES_INFO(pCtx);
   if (pResInfo->hasResult != DATA_SET_FLAG) {
-    if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
-      setVardataNull(pCtx->pOutput, pCtx->outputType);
-    } else {
-      setNull(pCtx->pOutput, pCtx->outputType, pCtx->outputBytes);
-    }
+    setNull(pCtx->pOutput, pCtx->outputType, pCtx->outputBytes);
   }
   
   doFinalizer(pCtx);
@@ -414,10 +412,7 @@ static void count_function(SQLFunctionCtx *pCtx) {
         numOfElem += 1;
       }
     } else {
-      /*
-       * when counting on the primary time stamp column and no statistics data is provided,
-       * simple use the size value
-       */
+      //when counting on the primary time stamp column and no statistics data is presented, use the size value directly.
       numOfElem = pCtx->size;
     }
   }
@@ -944,9 +939,9 @@ static void minMax_function(SQLFunctionCtx *pCtx, char *pOutput, int32_t isMin,
        *
        * The following codes of 3 lines will be removed later.
        */
-      if (index < 0 || index >= pCtx->size + pCtx->startOffset) {
-        index = 0;
-      }
+//      if (index < 0 || index >= pCtx->size + pCtx->startOffset) {
+//        index = 0;
+//      }
 
       // the index is the original position, not the relative position
       key = pCtx->ptsList[index];
@@ -3487,9 +3482,7 @@ static void arithmetic_function(SQLFunctionCtx *pCtx) {
   SArithmeticSupport *sas = (SArithmeticSupport *)pCtx->param[1].pz;
   
   arithmeticTreeTraverse(sas->pArithExpr->pExpr, pCtx->size, pCtx->pOutput, sas, pCtx->order, getArithColumnData);
-  
   pCtx->pOutput += pCtx->outputBytes * pCtx->size;
-  pCtx->param[1].pz = NULL;
 }
 
 static void arithmetic_function_f(SQLFunctionCtx *pCtx, int32_t index) {
@@ -3977,6 +3970,12 @@ static void interp_function_impl(SQLFunctionCtx *pCtx) {
       } else {
         assignVal(pCtx->pOutput, pCtx->start.ptr, pCtx->outputBytes, pCtx->inputType);
       }
+    } else if (type == TSDB_FILL_NEXT) {
+      if (IS_NUMERIC_TYPE(pCtx->inputType) || pCtx->inputType == TSDB_DATA_TYPE_BOOL) {
+        SET_TYPED_DATA(pCtx->pOutput, pCtx->inputType, pCtx->end.val);
+      } else {
+        assignVal(pCtx->pOutput, pCtx->end.ptr, pCtx->outputBytes, pCtx->inputType);
+      }
     } else if (type == TSDB_FILL_LINEAR) {
       SPoint point1 = {.key = pCtx->start.key, .val = &pCtx->start.val};
       SPoint point2 = {.key = pCtx->end.key, .val = &pCtx->end.val};

src/query/src/qUtil.c

@@ -20,6 +20,14 @@
 #include "qExecutor.h"
 #include "qUtil.h"
 #include "tbuffer.h"
+#include "tlosertree.h"
+#include "queryLog.h"
+
+typedef struct SCompSupporter {
+  STableQueryInfo **pTableQueryInfo;
+  int32_t          *rowIndex;
+  int32_t           order;
+} SCompSupporter;
 
 int32_t getOutputInterResultBufSize(SQuery* pQuery) {
   int32_t size = 0;
@@ -322,4 +330,243 @@ void freeInterResult(void* param) {
   }
 
   taosArrayDestroy(pResult->pResult);
-}
\ No newline at end of file
+}
+
+void cleanupGroupResInfo(SGroupResInfo* pGroupResInfo) {
+  assert(pGroupResInfo != NULL);
+
+  taosArrayDestroy(pGroupResInfo->pRows);
+  pGroupResInfo->pRows     = NULL;
+  pGroupResInfo->index     = 0;
+}
+
+void initGroupResInfo(SGroupResInfo* pGroupResInfo, SResultRowInfo* pResultInfo, int32_t offset) {
+  if (pGroupResInfo->pRows != NULL) {
+    taosArrayDestroy(pGroupResInfo->pRows);
+  }
+
+  pGroupResInfo->pRows = taosArrayFromList(pResultInfo->pResult, pResultInfo->size, POINTER_BYTES);
+  pGroupResInfo->index = offset;
+
+  assert(pGroupResInfo->index <= getNumOfTotalRes(pGroupResInfo));
+}
+
+bool hasRemainData(SGroupResInfo* pGroupResInfo) {
+  if (pGroupResInfo->pRows == NULL) {
+    return false;
+  }
+
+  return pGroupResInfo->index < taosArrayGetSize(pGroupResInfo->pRows);
+}
+
+bool incNextGroup(SGroupResInfo* pGroupResInfo) {
+  return (++pGroupResInfo->currentGroup) < pGroupResInfo->totalGroup;
+}
+
+int32_t getNumOfTotalRes(SGroupResInfo* pGroupResInfo) {
+  assert(pGroupResInfo != NULL);
+  if (pGroupResInfo->pRows == 0) {
+    return 0;
+  }
+
+  return taosArrayGetSize(pGroupResInfo->pRows);
+}
+
+static int64_t getNumOfResultWindowRes(SQueryRuntimeEnv* pRuntimeEnv, SResultRow *pResultRow) {
+  SQuery* pQuery = pRuntimeEnv->pQuery;
+
+  for (int32_t j = 0; j < pQuery->numOfOutput; ++j) {
+    int32_t functionId = pQuery->pExpr1[j].base.functionId;
+
+    /*
+     * ts, tag, tagprj function can not decide the output number of current query
+     * the number of output result is decided by main output
+     */
+    if (functionId == TSDB_FUNC_TS || functionId == TSDB_FUNC_TAG || functionId == TSDB_FUNC_TAGPRJ) {
+      continue;
+    }
+
+    SResultRowCellInfo *pResultInfo = getResultCell(pRuntimeEnv, pResultRow, j);
+    assert(pResultInfo != NULL);
+
+    if (pResultInfo->numOfRes > 0) {
+      return pResultInfo->numOfRes;
+    }
+  }
+
+  return 0;
+}
+
+static int32_t tableResultComparFn(const void *pLeft, const void *pRight, void *param) {
+  int32_t left  = *(int32_t *)pLeft;
+  int32_t right = *(int32_t *)pRight;
+
+  SCompSupporter *  supporter = (SCompSupporter *)param;
+
+  int32_t leftPos  = supporter->rowIndex[left];
+  int32_t rightPos = supporter->rowIndex[right];
+
+  /* left source is exhausted */
+  if (leftPos == -1) {
+    return 1;
+  }
+
+  /* right source is exhausted*/
+  if (rightPos == -1) {
+    return -1;
+  }
+
+  STableQueryInfo** pList = supporter->pTableQueryInfo;
+
+  SResultRowInfo *pWindowResInfo1 = &(pList[left]->resInfo);
+  SResultRow * pWindowRes1 = getResultRow(pWindowResInfo1, leftPos);
+  TSKEY leftTimestamp = pWindowRes1->win.skey;
+
+  SResultRowInfo *pWindowResInfo2 = &(pList[right]->resInfo);
+  SResultRow * pWindowRes2 = getResultRow(pWindowResInfo2, rightPos);
+  TSKEY rightTimestamp = pWindowRes2->win.skey;
+
+  if (leftTimestamp == rightTimestamp) {
+    return 0;
+  }
+
+  if (supporter->order == TSDB_ORDER_ASC) {
+    return (leftTimestamp > rightTimestamp)? 1:-1;
+  } else {
+    return (leftTimestamp < rightTimestamp)? 1:-1;
+  }
+}
+
+static int32_t mergeIntoGroupResultImpl(SQueryRuntimeEnv *pRuntimeEnv, SGroupResInfo* pGroupResInfo, SArray *pTableList, void* qinfo) {
+  bool ascQuery = QUERY_IS_ASC_QUERY(pRuntimeEnv->pQuery);
+
+  int32_t code = TSDB_CODE_SUCCESS;
+
+  int32_t *posList = NULL;
+  SLoserTreeInfo *pTree = NULL;
+  STableQueryInfo **pTableQueryInfoList = NULL;
+
+  size_t size = taosArrayGetSize(pTableList);
+  if (pGroupResInfo->pRows == NULL) {
+    pGroupResInfo->pRows = taosArrayInit(100, POINTER_BYTES);
+  }
+
+  posList = calloc(size, sizeof(int32_t));
+  pTableQueryInfoList = malloc(POINTER_BYTES * size);
+
+  if (pTableQueryInfoList == NULL || posList == NULL || pGroupResInfo->pRows == NULL || pGroupResInfo->pRows == NULL) {
+    qError("QInfo:%p failed alloc memory", qinfo);
+    code = TSDB_CODE_QRY_OUT_OF_MEMORY;
+    goto _end;
+  }
+
+  int32_t numOfTables = 0;
+  for (int32_t i = 0; i < size; ++i) {
+    STableQueryInfo *item = taosArrayGetP(pTableList, i);
+    if (item->resInfo.size > 0) {
+      pTableQueryInfoList[numOfTables++] = item;
+    }
+  }
+
+  // there is no data in current group
+  // no need to merge results since only one table in each group
+  if (numOfTables == 0) {
+    goto _end;
+  }
+
+  SCompSupporter cs = {pTableQueryInfoList, posList, pRuntimeEnv->pQuery->order.order};
+
+  int32_t ret = tLoserTreeCreate(&pTree, numOfTables, &cs, tableResultComparFn);
+  if (ret != TSDB_CODE_SUCCESS) {
+    code = TSDB_CODE_QRY_OUT_OF_MEMORY;
+    goto _end;
+  }
+
+  int64_t lastTimestamp = ascQuery? INT64_MIN:INT64_MAX;
+  int64_t startt = taosGetTimestampMs();
+
+  while (1) {
+    int32_t tableIndex = pTree->pNode[0].index;
+
+    SResultRowInfo *pWindowResInfo = &pTableQueryInfoList[tableIndex]->resInfo;
+    SResultRow  *pWindowRes = getResultRow(pWindowResInfo, cs.rowIndex[tableIndex]);
+
+    int64_t num = getNumOfResultWindowRes(pRuntimeEnv, pWindowRes);
+    if (num <= 0) {
+      cs.rowIndex[tableIndex] += 1;
+
+      if (cs.rowIndex[tableIndex] >= pWindowResInfo->size) {
+        cs.rowIndex[tableIndex] = -1;
+        if (--numOfTables == 0) { // all input sources are exhausted
+          break;
+        }
+      }
+    } else {
+      assert((pWindowRes->win.skey >= lastTimestamp && ascQuery) || (pWindowRes->win.skey <= lastTimestamp && !ascQuery));
+
+      if (pWindowRes->win.skey != lastTimestamp) {
+        taosArrayPush(pGroupResInfo->pRows, &pWindowRes);
+        pWindowRes->numOfRows = (uint32_t) num;
+      }
+
+      lastTimestamp = pWindowRes->win.skey;
+
+      // move to the next row of current entry
+      if ((++cs.rowIndex[tableIndex]) >= pWindowResInfo->size) {
+        cs.rowIndex[tableIndex] = -1;
+
+        // all input sources are exhausted
+        if ((--numOfTables) == 0) {
+          break;
+        }
+      }
+    }
+
+    tLoserTreeAdjust(pTree, tableIndex + pTree->numOfEntries);
+  }
+
+  int64_t endt = taosGetTimestampMs();
+
+  qDebug("QInfo:%p result merge completed for group:%d, elapsed time:%" PRId64 " ms", qinfo,
+         pGroupResInfo->currentGroup, endt - startt);
+
+  _end:
+  tfree(pTableQueryInfoList);
+  tfree(posList);
+  tfree(pTree);
+
+  return code;
+}
+
+int32_t mergeIntoGroupResult(SGroupResInfo* pGroupResInfo, SQInfo *pQInfo) {
+  int64_t st = taosGetTimestampUs();
+
+  while (pGroupResInfo->currentGroup < pGroupResInfo->totalGroup) {
+    SArray *group = GET_TABLEGROUP(pQInfo, pGroupResInfo->currentGroup);
+
+    int32_t ret = mergeIntoGroupResultImpl(&pQInfo->runtimeEnv, pGroupResInfo, group, pQInfo);
+    if (ret != TSDB_CODE_SUCCESS) {
+      return ret;
+    }
+
+    // this group generates at least one result, return results
+    if (taosArrayGetSize(pGroupResInfo->pRows) > 0) {
+      break;
+    }
+
+    qDebug("QInfo:%p no result in group %d, continue", pQInfo, pGroupResInfo->currentGroup);
+    cleanupGroupResInfo(pGroupResInfo);
+    incNextGroup(pGroupResInfo);
+  }
+
+  if (pGroupResInfo->currentGroup >= pGroupResInfo->totalGroup && !hasRemainData(pGroupResInfo)) {
+    SET_STABLE_QUERY_OVER(pQInfo);
+  }
+
+  int64_t elapsedTime = taosGetTimestampUs() - st;
+  qDebug("QInfo:%p merge res data into group, index:%d, total group:%d, elapsed time:%" PRId64 "us", pQInfo,
+         pGroupResInfo->currentGroup, pGroupResInfo->totalGroup, elapsedTime);
+
+  pQInfo->runtimeEnv.summary.firstStageMergeTime += elapsedTime;
+  return TSDB_CODE_SUCCESS;
+}

src/query/src/queryMain.c

+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "os.h"
+#include "qFill.h"
+#include "taosmsg.h"
+#include "tcache.h"
+#include "tglobal.h"
+
+#include "exception.h"
+#include "hash.h"
+#include "texpr.h"
+#include "qExecutor.h"
+#include "qResultbuf.h"
+#include "qUtil.h"
+#include "query.h"
+#include "queryLog.h"
+#include "tlosertree.h"
+#include "ttype.h"
+#include "tcompare.h"
+
+typedef struct SQueryMgmt {
+  pthread_mutex_t lock;
+  SCacheObj      *qinfoPool;      // query handle pool
+  int32_t         vgId;
+  bool            closed;
+} SQueryMgmt;
+
+static void queryMgmtKillQueryFn(void* handle) {
+  void** fp = (void**)handle;
+  qKillQuery(*fp);
+}
+
+static void freeqinfoFn(void *qhandle) {
+  void** handle = qhandle;
+  if (handle == NULL || *handle == NULL) {
+    return;
+  }
+
+  qKillQuery(*handle);
+  qDestroyQueryInfo(*handle);
+}
+
+void freeParam(SQueryParam *param) {
+  tfree(param->sql);
+  tfree(param->tagCond);
+  tfree(param->tbnameCond);
+  tfree(param->pTableIdList);
+  tfree(param->pExprMsg);
+  tfree(param->pSecExprMsg);
+  tfree(param->pExprs);
+  tfree(param->pSecExprs);
+  tfree(param->pGroupColIndex);
+  tfree(param->pTagColumnInfo);
+  tfree(param->pGroupbyExpr);
+  tfree(param->prevResult);
+}
+
+int32_t qCreateQueryInfo(void* tsdb, int32_t vgId, SQueryTableMsg* pQueryMsg, qinfo_t* pQInfo) {
+  assert(pQueryMsg != NULL && tsdb != NULL);
+
+  int32_t code = TSDB_CODE_SUCCESS;
+
+  SQueryParam param = {0};
+  code = convertQueryMsg(pQueryMsg, &param);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _over;
+  }
+
+  if (pQueryMsg->numOfTables <= 0) {
+    qError("Invalid number of tables to query, numOfTables:%d", pQueryMsg->numOfTables);
+    code = TSDB_CODE_QRY_INVALID_MSG;
+    goto _over;
+  }
+
+  if (param.pTableIdList == NULL || taosArrayGetSize(param.pTableIdList) == 0) {
+    qError("qmsg:%p, SQueryTableMsg wrong format", pQueryMsg);
+    code = TSDB_CODE_QRY_INVALID_MSG;
+    goto _over;
+  }
+
+  if ((code = createQueryFuncExprFromMsg(pQueryMsg, pQueryMsg->numOfOutput, &param.pExprs, param.pExprMsg, param.pTagColumnInfo)) != TSDB_CODE_SUCCESS) {
+    goto _over;
+  }
+
+  if (param.pSecExprMsg != NULL) {
+    if ((code = createQueryFuncExprFromMsg(pQueryMsg, pQueryMsg->secondStageOutput, &param.pSecExprs, param.pSecExprMsg, param.pTagColumnInfo)) != TSDB_CODE_SUCCESS) {
+      goto _over;
+    }
+  }
+
+  param.pGroupbyExpr = createGroupbyExprFromMsg(pQueryMsg, param.pGroupColIndex, &code);
+  if ((param.pGroupbyExpr == NULL && pQueryMsg->numOfGroupCols != 0) || code != TSDB_CODE_SUCCESS) {
+    goto _over;
+  }
+
+  bool isSTableQuery = false;
+  STableGroupInfo tableGroupInfo = {0};
+  int64_t st = taosGetTimestampUs();
+
+  if (TSDB_QUERY_HAS_TYPE(pQueryMsg->queryType, TSDB_QUERY_TYPE_TABLE_QUERY)) {
+    STableIdInfo *id = taosArrayGet(param.pTableIdList, 0);
+
+    qDebug("qmsg:%p query normal table, uid:%"PRId64", tid:%d", pQueryMsg, id->uid, id->tid);
+    if ((code = tsdbGetOneTableGroup(tsdb, id->uid, pQueryMsg->window.skey, &tableGroupInfo)) != TSDB_CODE_SUCCESS) {
+      goto _over;
+    }
+  } else if (TSDB_QUERY_HAS_TYPE(pQueryMsg->queryType, TSDB_QUERY_TYPE_MULTITABLE_QUERY|TSDB_QUERY_TYPE_STABLE_QUERY)) {
+    isSTableQuery = true;
+
+    // also note there's possibility that only one table in the super table
+    if (!TSDB_QUERY_HAS_TYPE(pQueryMsg->queryType, TSDB_QUERY_TYPE_MULTITABLE_QUERY)) {
+      STableIdInfo *id = taosArrayGet(param.pTableIdList, 0);
+
+      // group by normal column, do not pass the group by condition to tsdb to group table into different group
+      int32_t numOfGroupByCols = pQueryMsg->numOfGroupCols;
+      if (pQueryMsg->numOfGroupCols == 1 && !TSDB_COL_IS_TAG(param.pGroupColIndex->flag)) {
+        numOfGroupByCols = 0;
+      }
+
+      qDebug("qmsg:%p query stable, uid:%"PRId64", tid:%d", pQueryMsg, id->uid, id->tid);
+      code = tsdbQuerySTableByTagCond(tsdb, id->uid, pQueryMsg->window.skey, param.tagCond, pQueryMsg->tagCondLen,
+                                      pQueryMsg->tagNameRelType, param.tbnameCond, &tableGroupInfo, param.pGroupColIndex, numOfGroupByCols);
+
+      if (code != TSDB_CODE_SUCCESS) {
+        qError("qmsg:%p failed to query stable, reason: %s", pQueryMsg, tstrerror(code));
+        goto _over;
+      }
+    } else {
+      code = tsdbGetTableGroupFromIdList(tsdb, param.pTableIdList, &tableGroupInfo);
+      if (code != TSDB_CODE_SUCCESS) {
+        goto _over;
+      }
+
+      qDebug("qmsg:%p query on %" PRIzu " tables in one group from client", pQueryMsg, tableGroupInfo.numOfTables);
+    }
+
+    int64_t el = taosGetTimestampUs() - st;
+    qDebug("qmsg:%p tag filter completed, numOfTables:%" PRIzu ", elapsed time:%"PRId64"us", pQueryMsg, tableGroupInfo.numOfTables, el);
+  } else {
+    assert(0);
+  }
+
+  code = checkForQueryBuf(tableGroupInfo.numOfTables);
+  if (code != TSDB_CODE_SUCCESS) {  // not enough query buffer, abort
+    goto _over;
+  }
+
+  (*pQInfo) = createQInfoImpl(pQueryMsg, param.pGroupbyExpr, param.pExprs, param.pSecExprs, &tableGroupInfo, param.pTagColumnInfo, isSTableQuery, param.sql);
+
+  param.sql    = NULL;
+  param.pExprs = NULL;
+  param.pSecExprs = NULL;
+  param.pGroupbyExpr = NULL;
+  param.pTagColumnInfo = NULL;
+
+  if ((*pQInfo) == NULL) {
+    code = TSDB_CODE_QRY_OUT_OF_MEMORY;
+    goto _over;
+  }
+
+  code = initQInfo(pQueryMsg, tsdb, vgId, *pQInfo, &param, isSTableQuery);
+
+  _over:
+  if (param.pGroupbyExpr != NULL) {
+    taosArrayDestroy(param.pGroupbyExpr->columnInfo);
+  }
+
+  taosArrayDestroy(param.pTableIdList);
+  param.pTableIdList = NULL;
+
+  freeParam(&param);
+
+  for (int32_t i = 0; i < pQueryMsg->numOfCols; i++) {
+    SColumnInfo* column = pQueryMsg->colList + i;
+    freeColumnFilterInfo(column->filters, column->numOfFilters);
+  }
+
+  //pQInfo already freed in initQInfo, but *pQInfo may not pointer to null;
+  if (code != TSDB_CODE_SUCCESS) {
+    *pQInfo = NULL;
+  }
+
+  // if failed to add ref for all tables in this query, abort current query
+  return code;
+}
+
+bool qTableQuery(qinfo_t qinfo) {
+  SQInfo *pQInfo = (SQInfo *)qinfo;
+  assert(pQInfo && pQInfo->signature == pQInfo);
+  int64_t threadId = taosGetSelfPthreadId();
+
+  int64_t curOwner = 0;
+  if ((curOwner = atomic_val_compare_exchange_64(&pQInfo->owner, 0, threadId)) != 0) {
+    qError("QInfo:%p qhandle is now executed by thread:%p", pQInfo, (void*) curOwner);
+    pQInfo->code = TSDB_CODE_QRY_IN_EXEC;
+    return false;
+  }
+
+  pQInfo->startExecTs = taosGetTimestampSec();
+
+  if (isQueryKilled(pQInfo)) {
+    qDebug("QInfo:%p it is already killed, abort", pQInfo);
+    return doBuildResCheck(pQInfo);
+  }
+
+  if (pQInfo->tableqinfoGroupInfo.numOfTables == 0) {
+    qDebug("QInfo:%p no table exists for query, abort", pQInfo);
+    setQueryStatus(pQInfo->runtimeEnv.pQuery, QUERY_COMPLETED);
+    return doBuildResCheck(pQInfo);
+  }
+
+  // error occurs, record the error code and return to client
+  int32_t ret = setjmp(pQInfo->runtimeEnv.env);
+  if (ret != TSDB_CODE_SUCCESS) {
+    pQInfo->code = ret;
+    qDebug("QInfo:%p query abort due to error/cancel occurs, code:%s", pQInfo, tstrerror(pQInfo->code));
+    return doBuildResCheck(pQInfo);
+  }
+
+  qDebug("QInfo:%p query task is launched", pQInfo);
+
+  SQueryRuntimeEnv* pRuntimeEnv = &pQInfo->runtimeEnv;
+  if (onlyQueryTags(pQInfo->runtimeEnv.pQuery)) {
+    assert(pQInfo->runtimeEnv.pQueryHandle == NULL);
+    buildTagQueryResult(pQInfo);
+  } else if (pQInfo->runtimeEnv.stableQuery) {
+    stableQueryImpl(pQInfo);
+  } else if (pQInfo->runtimeEnv.queryBlockDist){
+    buildTableBlockDistResult(pQInfo);
+  } else {
+    tableQueryImpl(pQInfo);
+  }
+
+  SQuery* pQuery = pRuntimeEnv->pQuery;
+  if (isQueryKilled(pQInfo)) {
+    qDebug("QInfo:%p query is killed", pQInfo);
+  } else if (pQuery->rec.rows == 0) {
+    qDebug("QInfo:%p over, %" PRIzu " tables queried, %"PRId64" rows are returned", pQInfo, pQInfo->tableqinfoGroupInfo.numOfTables, pQuery->rec.total);
+  } else {
+    qDebug("QInfo:%p query paused, %" PRId64 " rows returned, numOfTotal:%" PRId64 " rows",
+           pQInfo, pQuery->rec.rows, pQuery->rec.total + pQuery->rec.rows);
+  }
+
+  return doBuildResCheck(pQInfo);
+}
+
+int32_t qRetrieveQueryResultInfo(qinfo_t qinfo, bool* buildRes, void* pRspContext) {
+  SQInfo *pQInfo = (SQInfo *)qinfo;
+
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
+    qError("QInfo:%p invalid qhandle", pQInfo);
+    return TSDB_CODE_QRY_INVALID_QHANDLE;
+  }
+
+  *buildRes = false;
+  if (IS_QUERY_KILLED(pQInfo)) {
+    qDebug("QInfo:%p query is killed, code:0x%08x", pQInfo, pQInfo->code);
+    return pQInfo->code;
+  }
+
+  int32_t code = TSDB_CODE_SUCCESS;
+
+  if (tsRetrieveBlockingModel) {
+    pQInfo->rspContext = pRspContext;
+    tsem_wait(&pQInfo->ready);
+    *buildRes = true;
+    code = pQInfo->code;
+  } else {
+    SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
+
+    pthread_mutex_lock(&pQInfo->lock);
+
+    assert(pQInfo->rspContext == NULL);
+    if (pQInfo->dataReady == QUERY_RESULT_READY) {
+      *buildRes = true;
+      qDebug("QInfo:%p retrieve result info, rowsize:%d, rows:%" PRId64 ", code:%s", pQInfo, pQuery->resultRowSize,
+             pQuery->rec.rows, tstrerror(pQInfo->code));
+    } else {
+      *buildRes = false;
+      qDebug("QInfo:%p retrieve req set query return result after paused", pQInfo);
+      pQInfo->rspContext = pRspContext;
+      assert(pQInfo->rspContext != NULL);
+    }
+
+    code = pQInfo->code;
+    pthread_mutex_unlock(&pQInfo->lock);
+  }
+
+  return code;
+}
+
+int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp **pRsp, int32_t *contLen, bool* continueExec) {
+  SQInfo *pQInfo = (SQInfo *)qinfo;
+
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
+    return TSDB_CODE_QRY_INVALID_QHANDLE;
+  }
+
+  SQueryRuntimeEnv* pRuntimeEnv = &pQInfo->runtimeEnv;
+  SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
+  size_t  size = getResultSize(pQInfo, &pQuery->rec.rows);
+
+  size += sizeof(int32_t);
+  size += sizeof(STableIdInfo) * taosHashGetSize(pQInfo->arrTableIdInfo);
+
+  *contLen = (int32_t)(size + sizeof(SRetrieveTableRsp));
+
+  // current solution only avoid crash, but cannot return error code to client
+  *pRsp = (SRetrieveTableRsp *)rpcMallocCont(*contLen);
+  if (*pRsp == NULL) {
+    return TSDB_CODE_QRY_OUT_OF_MEMORY;
+  }
+
+  (*pRsp)->numOfRows = htonl((int32_t)pQuery->rec.rows);
+
+  if (pQInfo->code == TSDB_CODE_SUCCESS) {
+    (*pRsp)->offset   = htobe64(pQuery->limit.offset);
+    (*pRsp)->useconds = htobe64(pRuntimeEnv->summary.elapsedTime);
+  } else {
+    (*pRsp)->offset   = 0;
+    (*pRsp)->useconds = htobe64(pRuntimeEnv->summary.elapsedTime);
+  }
+
+  (*pRsp)->precision = htons(pQuery->precision);
+  if (pQuery->rec.rows > 0 && pQInfo->code == TSDB_CODE_SUCCESS) {
+    doDumpQueryResult(pQInfo, (*pRsp)->data);
+  } else {
+    setQueryStatus(pQuery, QUERY_OVER);
+  }
+
+  pQInfo->rspContext = NULL;
+  pQInfo->dataReady  = QUERY_RESULT_NOT_READY;
+
+  if (IS_QUERY_KILLED(pQInfo) || Q_STATUS_EQUAL(pQuery->status, QUERY_OVER)) {
+    // here current thread hold the refcount, so it is safe to free tsdbQueryHandle.
+    *continueExec = false;
+    (*pRsp)->completed = 1;  // notify no more result to client
+  } else {
+    *continueExec = true;
+    qDebug("QInfo:%p has more results to retrieve", pQInfo);
+  }
+
+  return pQInfo->code;
+}
+
+void* qGetResultRetrieveMsg(qinfo_t qinfo) {
+  SQInfo* pQInfo = (SQInfo*) qinfo;
+  assert(pQInfo != NULL);
+
+  return pQInfo->rspContext;
+}
+
+int32_t qKillQuery(qinfo_t qinfo) {
+  SQInfo *pQInfo = (SQInfo *)qinfo;
+
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
+    return TSDB_CODE_QRY_INVALID_QHANDLE;
+  }
+
+  setQueryKilled(pQInfo);
+
+  // Wait for the query executing thread being stopped/
+  // Once the query is stopped, the owner of qHandle will be cleared immediately.
+  while (pQInfo->owner != 0) {
+    taosMsleep(100);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t qQueryCompleted(qinfo_t qinfo) {
+  SQInfo *pQInfo = (SQInfo *)qinfo;
+
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
+    return TSDB_CODE_QRY_INVALID_QHANDLE;
+  }
+
+  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
+  return isQueryKilled(pQInfo) || Q_STATUS_EQUAL(pQuery->status, QUERY_OVER);
+}
+
+void qDestroyQueryInfo(qinfo_t qHandle) {
+  SQInfo* pQInfo = (SQInfo*) qHandle;
+  if (!isValidQInfo(pQInfo)) {
+    return;
+  }
+
+  qDebug("QInfo:%p query completed", pQInfo);
+  queryCostStatis(pQInfo);   // print the query cost summary
+  freeQInfo(pQInfo);
+}
+
+void* qOpenQueryMgmt(int32_t vgId) {
+  const int32_t refreshHandleInterval = 30; // every 30 seconds, refresh handle pool
+
+  char cacheName[128] = {0};
+  sprintf(cacheName, "qhandle_%d", vgId);
+
+  SQueryMgmt* pQueryMgmt = calloc(1, sizeof(SQueryMgmt));
+  if (pQueryMgmt == NULL) {
+    terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  pQueryMgmt->qinfoPool = taosCacheInit(TSDB_CACHE_PTR_KEY, refreshHandleInterval, true, freeqinfoFn, cacheName);
+  pQueryMgmt->closed    = false;
+  pQueryMgmt->vgId      = vgId;
+
+  pthread_mutex_init(&pQueryMgmt->lock, NULL);
+
+  qDebug("vgId:%d, open querymgmt success", vgId);
+  return pQueryMgmt;
+}
+
+void qQueryMgmtNotifyClosed(void* pQMgmt) {
+  if (pQMgmt == NULL) {
+    return;
+  }
+
+  SQueryMgmt* pQueryMgmt = pQMgmt;
+  qDebug("vgId:%d, set querymgmt closed, wait for all queries cancelled", pQueryMgmt->vgId);
+
+  pthread_mutex_lock(&pQueryMgmt->lock);
+  pQueryMgmt->closed = true;
+  pthread_mutex_unlock(&pQueryMgmt->lock);
+
+  taosCacheRefresh(pQueryMgmt->qinfoPool, queryMgmtKillQueryFn);
+}
+
+void qQueryMgmtReOpen(void *pQMgmt) {
+  if (pQMgmt == NULL) {
+    return;
+  }
+
+  SQueryMgmt *pQueryMgmt = pQMgmt;
+  qDebug("vgId:%d, set querymgmt reopen", pQueryMgmt->vgId);
+
+  pthread_mutex_lock(&pQueryMgmt->lock);
+  pQueryMgmt->closed = false;
+  pthread_mutex_unlock(&pQueryMgmt->lock);
+}
+
+void qCleanupQueryMgmt(void* pQMgmt) {
+  if (pQMgmt == NULL) {
+    return;
+  }
+
+  SQueryMgmt* pQueryMgmt = pQMgmt;
+  int32_t vgId = pQueryMgmt->vgId;
+
+  assert(pQueryMgmt->closed);
+
+  SCacheObj* pqinfoPool = pQueryMgmt->qinfoPool;
+  pQueryMgmt->qinfoPool = NULL;
+
+  taosCacheCleanup(pqinfoPool);
+  pthread_mutex_destroy(&pQueryMgmt->lock);
+  tfree(pQueryMgmt);
+
+  qDebug("vgId:%d, queryMgmt cleanup completed", vgId);
+}
+
+void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
+  if (pMgmt == NULL) {
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
+    return NULL;
+  }
+
+  SQueryMgmt *pQueryMgmt = pMgmt;
+  if (pQueryMgmt->qinfoPool == NULL) {
+    qError("QInfo:%p failed to add qhandle into qMgmt, since qMgmt is closed", (void *)qInfo);
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
+    return NULL;
+  }
+
+  pthread_mutex_lock(&pQueryMgmt->lock);
+  if (pQueryMgmt->closed) {
+    pthread_mutex_unlock(&pQueryMgmt->lock);
+    qError("QInfo:%p failed to add qhandle into cache, since qMgmt is colsing", (void *)qInfo);
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
+    return NULL;
+  } else {
+    TSDB_CACHE_PTR_TYPE handleVal = (TSDB_CACHE_PTR_TYPE) qInfo;
+    void** handle = taosCachePut(pQueryMgmt->qinfoPool, &handleVal, sizeof(TSDB_CACHE_PTR_TYPE), &qInfo, sizeof(TSDB_CACHE_PTR_TYPE),
+                                 (getMaximumIdleDurationSec()*1000));
+    pthread_mutex_unlock(&pQueryMgmt->lock);
+
+    return handle;
+  }
+}
+
+void** qAcquireQInfo(void* pMgmt, uint64_t _key) {
+  SQueryMgmt *pQueryMgmt = pMgmt;
+
+  if (pQueryMgmt->closed) {
+    terrno = TSDB_CODE_VND_INVALID_VGROUP_ID;
+    return NULL;
+  }
+
+  if (pQueryMgmt->qinfoPool == NULL) {
+    terrno = TSDB_CODE_QRY_INVALID_QHANDLE;
+    return NULL;
+  }
+
+  TSDB_CACHE_PTR_TYPE key = (TSDB_CACHE_PTR_TYPE)_key;
+  void** handle = taosCacheAcquireByKey(pQueryMgmt->qinfoPool, &key, sizeof(TSDB_CACHE_PTR_TYPE));
+  if (handle == NULL || *handle == NULL) {
+    terrno = TSDB_CODE_QRY_INVALID_QHANDLE;
+    return NULL;
+  } else {
+    return handle;
+  }
+}
+
+void** qReleaseQInfo(void* pMgmt, void* pQInfo, bool freeHandle) {
+  SQueryMgmt *pQueryMgmt = pMgmt;
+  if (pQueryMgmt->qinfoPool == NULL) {
+    return NULL;
+  }
+
+  taosCacheRelease(pQueryMgmt->qinfoPool, pQInfo, freeHandle);
+  return 0;
+}

src/util/inc/tarray.h

@@ -125,7 +125,7 @@ void taosArrayRemove(SArray* pArray, size_t index);
  * @param pDst
  * @param pSrc
  */
-void taosArrayCopy(SArray* pDst, const SArray* pSrc);
+SArray* taosArrayFromList(const void* src, size_t size, size_t elemSize);
 
 /**
  * clone a new array

src/util/src/tarray.c

@@ -156,23 +156,14 @@ void taosArrayRemove(SArray* pArray, size_t index) {
   pArray->size -= 1;
 }
 
-void taosArrayCopy(SArray* pDst, const SArray* pSrc) {
-  assert(pSrc != NULL && pDst != NULL);
-  
-  if (pDst->capacity < pSrc->size) {
-    void* pData = realloc(pDst->pData, pSrc->size * pSrc->elemSize);
-    if (pData == NULL) { // todo handle oom
-    
-    } else {
-      pDst->pData = pData;
-      pDst->capacity = pSrc->size;
-    }
-  }
-  
-  memcpy(pDst->pData, pSrc->pData, pSrc->elemSize * pSrc->size);
-  pDst->elemSize = pSrc->elemSize;
-  pDst->capacity = pSrc->size;
-  pDst->size = pSrc->size;
+SArray* taosArrayFromList(const void* src, size_t size, size_t elemSize) {
+  assert(src != NULL && elemSize > 0);
+  SArray* pDst = taosArrayInit(size, elemSize);
+
+  memcpy(pDst->pData, src, elemSize * size);
+  pDst->size = size;
+
+  return pDst;
 }
 
 SArray* taosArrayDup(const SArray* pSrc) {

tests/script/general/parser/limit2_query.sim

@@ -143,6 +143,97 @@ if $data11 != -1 then
   return -1
 endi
 
+sql select max(c1) from lm2_tb0 where ts >= 1537146000000 and ts <= 1543145400000 interval(5m) fill(value, -1000, -2) limit 8200
+if $rows != 8200 then
+  return -1
+endi
+
+sql select max(c1) from lm2_tb0 where ts >= 1537146000000 and ts <= 1543145400000 interval(5m) fill(value, -1000, -2) limit 10 offset 8190;
+if $rows != 10 then
+  return -1
+endi
+
+if $data00 != @18-10-15 19:30:00.000@ then
+  return -1
+endi
+
+if $data01 != 5 then
+  return -1
+endi
+
+if $data10 != @18-10-15 19:35:00.000@ then
+  return -1
+endi
+
+if $data11 != -1000 then
+  return -1
+endi
+
+if $data20 != @18-10-15 19:40:00.000@ then
+  return -1
+endi
+
+if $data21 != 6 then
+  return -1
+endi
+
+if $data30 != @18-10-15 19:45:00.000@ then
+  return -1
+endi
+
+if $data31 != -1000 then
+  return -1
+endi
+
+sql select max(c1) from lm2_tb0 where ts >= 1537146000000 and ts <= 1543145400000 interval(5m) fill(value, -1000, -2) limit 10 offset 10001;
+if $rows != 10 then
+  return -1
+endi
+
+if $data00 != @18-10-22 02:25:00.000@ then
+  return -1
+endi
+
+if $data01 != -1000 then
+  return -1
+endi
+
+if $data10 != @18-10-22 02:30:00.000@ then
+  return -1
+endi
+
+if $data11 != 1 then
+  return -1
+endi
+
+if $data20 != @18-10-22 02:35:00.000@ then
+  return -1
+endi
+
+if $data21 != -1000 then
+  return -1
+endi
+
+if $data30 != @18-10-22 02:40:00.000@ then
+  return -1
+endi
+
+if $data31 != 2 then
+  return -1
+endi
+
+sql select max(c1) from lm2_tb0 where ts >= 1537146000000 and ts <= 1543145400000 interval(5m) fill(value, -1000, -2) limit 10000 offset 10001;
+print ====> needs to validate the last row result
+if $rows != 9998 then
+  return -1
+endi
+
+
+sql select max(c1) from lm2_tb0 where ts >= 1537146000000 and ts <= 1543145400000 interval(5m) fill(value, -1000, -2) limit 100 offset 20001;
+if $rows != 0 then
+  return -1
+endi
+
 # tb + interval + fill(linear) + limit offset
 $limit = $rowNum
 $offset = $limit / 2

tests/script/general/parser/testSuite.sim

@@ -53,32 +53,32 @@
 #run general/parser/limit1_tblocks100.sim
 #sleep 100
 #run general/parser/limit2.sim
-#sleep 100
-#run general/parser/mixed_blocks.sim
-#sleep 100
-#run general/parser/nchar.sim
-#sleep 100
-#run general/parser/null_char.sim
-#sleep 100
-#run general/parser/selectResNum.sim
-#sleep 100
-#run general/parser/select_across_vnodes.sim
-#sleep 100
-#run general/parser/select_from_cache_disk.sim
-#sleep 100
-#run general/parser/set_tag_vals.sim
-#sleep 100
-#run general/parser/single_row_in_tb.sim
-#sleep 100
-#run general/parser/slimit.sim
-#sleep 100
-#run general/parser/slimit1.sim
-#sleep 100
-#run general/parser/slimit_alter_tags.sim
-#sleep 100
-#run general/parser/tbnameIn.sim
-#sleep 100
-#run general/parser/slimit_alter_tags.sim  # persistent failed
+sleep 100
+run general/parser/mixed_blocks.sim
+sleep 100
+run general/parser/nchar.sim
+sleep 100
+run general/parser/null_char.sim
+sleep 100
+run general/parser/selectResNum.sim
+sleep 100
+run general/parser/select_across_vnodes.sim
+sleep 100
+run general/parser/select_from_cache_disk.sim
+sleep 100
+run general/parser/set_tag_vals.sim
+sleep 100
+run general/parser/single_row_in_tb.sim
+sleep 100
+run general/parser/slimit.sim
+sleep 100
+run general/parser/slimit1.sim
+sleep 100
+run general/parser/slimit_alter_tags.sim
+sleep 100
+run general/parser/tbnameIn.sim
+sleep 100
+run general/parser/slimit_alter_tags.sim  # persistent failed
 sleep 100
 run general/parser/join.sim
 sleep 100