/*
 * 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 "tsdb.h"
#include "vnode.h"

#define ASCENDING_TRAVERSE(o)      (o == TSDB_ORDER_ASC)
#define QH_GET_NUM_OF_COLS(handle) ((size_t)(taosArrayGetSize((handle)->pResBlock->pDataBlock)))

#define GET_FILE_DATA_BLOCK_INFO(_checkInfo, _block)                                      \
  ((SDataBlockInfo){.window = {.skey = (_block)->minKey.ts, .ekey = (_block)->maxKey.ts}, \
                    .rows = (_block)->numOfRows,                                          \
                    .uid = (_checkInfo)->tableId})

enum {
  TSDB_QUERY_TYPE_ALL = 1,
  TSDB_QUERY_TYPE_LAST = 2,
};

enum {
  TSDB_CACHED_TYPE_NONE = 0,
  TSDB_CACHED_TYPE_LASTROW = 1,
  TSDB_CACHED_TYPE_LAST = 2,
};

typedef struct SQueryFilePos {
  int32_t     fid;
  int32_t     slot;
  int32_t     pos;
  int64_t     lastKey;
  int32_t     rows;
  bool        mixBlock;
  bool        blockCompleted;
  STimeWindow win;
} SQueryFilePos;

typedef struct SDataBlockLoadInfo {
  SDFileSet* fileGroup;
  int32_t    slot;
  uint64_t   uid;
  SArray*    pLoadedCols;
} SDataBlockLoadInfo;

typedef struct SLoadCompBlockInfo {
  int32_t tid; /* table tid */
  int32_t fileId;
} SLoadCompBlockInfo;

enum {
  CHECKINFO_CHOSEN_MEM = 0,
  CHECKINFO_CHOSEN_IMEM = 1,
  CHECKINFO_CHOSEN_BOTH = 2  // for update=2(merge case)
};

typedef struct STableCheckInfo {
  uint64_t     suid;
  uint64_t     tableId;
  TSKEY        lastKey;
  SBlockInfo*  pCompInfo;
  int32_t      compSize;
  int32_t      numOfBlocks : 29;  // number of qualified data blocks not the original blocks
  uint8_t      chosen : 2;        // indicate which iterator should move forward
  bool         initBuf : 1;       // whether to initialize the in-memory skip list iterator or not
  STbDataIter* iter;              // mem buffer skip list iterator
  STbDataIter* iiter;             // imem buffer skip list iterator
} STableCheckInfo;

typedef struct STableBlockInfo {
  SBlock*          compBlock;
  STableCheckInfo* pTableCheckInfo;
} STableBlockInfo;

typedef struct SBlockOrderSupporter {
  int32_t           numOfTables;
  STableBlockInfo** pDataBlockInfo;
  int32_t*          blockIndexArray;
  int32_t*          numOfBlocksPerTable;
} SBlockOrderSupporter;

typedef struct SIOCostSummary {
  int64_t blockLoadTime;
  int64_t statisInfoLoadTime;
  int64_t checkForNextTime;
  int64_t headFileLoad;
  int64_t headFileLoadTime;
} SIOCostSummary;

typedef struct SBlockLoadSuppInfo {
  SColumnDataAgg*  pstatis;
  SColumnDataAgg** plist;
  SArray*          defaultLoadColumn;  // default load column
  int32_t*         slotIds;            // colId to slotId
} SBlockLoadSuppInfo;

typedef struct STsdbReadHandle {
  STsdb*        pTsdb;
  uint64_t      suid;
  SQueryFilePos cur;  // current position
  int16_t       order;
  STimeWindow   window;  // the primary query time window that applies to all queries
  //  SColumnDataAgg* statis;  // query level statistics, only one table block statistics info exists at any time
  //  SColumnDataAgg** pstatis;// the ptr array list to return to caller
  int32_t      numOfBlocks;
  SSDataBlock* pResBlock;
  //  SArray* pColumns;  // column list, SColumnInfoData array list
  bool    locateStart;
  int32_t outputCapacity;
  int32_t realNumOfRows;
  SArray* pTableCheckInfo;  // SArray<STableCheckInfo>
  int32_t activeIndex;
  bool    checkFiles;               // check file stage
  int8_t  cachelastrow;             // check if last row cached
  bool    loadExternalRow;          // load time window external data rows
  bool    currentLoadExternalRows;  // current load external rows
  int32_t loadType;                 // block load type
  char*   idStr;                    // query info handle, for debug purpose
  int32_t type;  // query type: retrieve all data blocks, 2. retrieve only last row, 3. retrieve direct prev|next rows
  SDFileSet*         pFileGroup;
  SFSIter            fileIter;
  SReadH             rhelper;
  STableBlockInfo*   pDataBlockInfo;
  SDataCols*         pDataCols;         // in order to hold current file data block
  int32_t            allocSize;         // allocated data block size
  SDataBlockLoadInfo dataBlockLoadInfo; /* record current block load information */
  SLoadCompBlockInfo compBlockLoadInfo; /* record current compblock information in SQueryAttr */
  SBlockLoadSuppInfo suppInfo;
  SArray*            prev;  // previous row which is before than time window
  SArray*            next;  // next row which is after the query time window
  SIOCostSummary     cost;
  STSchema*          pSchema;
} STsdbReadHandle;

static STimeWindow updateLastrowForEachGroup(STableListInfo* pList);
static int32_t     checkForCachedLastRow(STsdbReadHandle* pTsdbReadHandle, STableListInfo* pList);
static int32_t     checkForCachedLast(STsdbReadHandle* pTsdbReadHandle);
// static int32_t tsdbGetCachedLastRow(STable* pTable, STSRow** pRes, TSKEY* lastKey);

static void    changeQueryHandleForInterpQuery(tsdbReaderT pHandle);
static void    doMergeTwoLevelData(STsdbReadHandle* pTsdbReadHandle, STableCheckInfo* pCheckInfo, SBlock* pBlock);
static int32_t tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int maxRowsToRead, STimeWindow* win,
                                     STsdbReadHandle* pTsdbReadHandle);
static int32_t tsdbCheckInfoCompar(const void* key1, const void* key2);
// static int32_t doGetExternalRow(STsdbReadHandle* pTsdbReadHandle, int16_t type, void* pMemRef);
// static void*   doFreeColumnInfoData(SArray* pColumnInfoData);
// static void*   destroyTableCheckInfo(SArray* pTableCheckInfo);
static bool tsdbGetExternalRow(tsdbReaderT pHandle);

static STsdb* getTsdbByRetentions(SVnode* pVnode, STsdbReadHandle* pReadHandle, TSKEY winSKey, SRetention* retentions);

static void tsdbInitDataBlockLoadInfo(SDataBlockLoadInfo* pBlockLoadInfo) {
  pBlockLoadInfo->slot = -1;
  pBlockLoadInfo->uid = 0;
  pBlockLoadInfo->fileGroup = NULL;
}

static void tsdbInitCompBlockLoadInfo(SLoadCompBlockInfo* pCompBlockLoadInfo) {
  pCompBlockLoadInfo->tid = -1;
  pCompBlockLoadInfo->fileId = -1;
}

static SArray* getColumnIdList(STsdbReadHandle* pTsdbReadHandle) {
  size_t numOfCols = QH_GET_NUM_OF_COLS(pTsdbReadHandle);
  assert(numOfCols <= TSDB_MAX_COLUMNS);

  SArray* pIdList = taosArrayInit(numOfCols, sizeof(int16_t));
  for (int32_t i = 0; i < numOfCols; ++i) {
    SColumnInfoData* pCol = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
    taosArrayPush(pIdList, &pCol->info.colId);
  }

  return pIdList;
}

static SArray* getDefaultLoadColumns(STsdbReadHandle* pTsdbReadHandle, bool loadTS) {
  SArray* pLocalIdList = getColumnIdList(pTsdbReadHandle);

  // check if the primary time stamp column needs to load
  int16_t colId = *(int16_t*)taosArrayGet(pLocalIdList, 0);

  // the primary timestamp column does not be included in the the specified load column list, add it
  if (loadTS && colId != PRIMARYKEY_TIMESTAMP_COL_ID) {
    int16_t columnId = PRIMARYKEY_TIMESTAMP_COL_ID;
    taosArrayInsert(pLocalIdList, 0, &columnId);
  }

  return pLocalIdList;
}

int64_t tsdbGetNumOfRowsInMemTable(tsdbReaderT* pHandle) {
  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)pHandle;

  int64_t    rows = 0;
  SMemTable* pMemTable = NULL;  // pTsdbReadHandle->pMemTable;
  if (pMemTable == NULL) {
    return rows;
  }

  size_t size = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
  for (int32_t i = 0; i < size; ++i) {
    STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);

    //    if (pMemT && pCheckInfo->tableId < pMemT->maxTables) {
    //      pMem = pMemT->tData[pCheckInfo->tableId];
    //      rows += (pMem && pMem->uid == pCheckInfo->tableId) ? pMem->numOfRows : 0;
    //    }
    //    if (pIMemT && pCheckInfo->tableId < pIMemT->maxTables) {
    //      pIMem = pIMemT->tData[pCheckInfo->tableId];
    //      rows += (pIMem && pIMem->uid == pCheckInfo->tableId) ? pIMem->numOfRows : 0;
    //    }
  }
  return rows;
}

static SArray* createCheckInfoFromUid(STsdbReadHandle* pTsdbReadHandle, int64_t uid) {
  SArray* pTableCheckInfo = taosArrayInit(1, sizeof(STableCheckInfo));
  if (pTableCheckInfo == NULL) {
    return NULL;
  }
  STableCheckInfo info = {
      .tableId = uid,
  };
  info.suid = pTsdbReadHandle->suid;

  taosArrayPush(pTableCheckInfo, &info);
  tsdbDebug("%p check table uid:%" PRId64 " from lastKey:%" PRId64 " %s", pTsdbReadHandle, info.tableId, info.lastKey,
            pTsdbReadHandle->idStr);
  return pTableCheckInfo;
}

static SArray* createCheckInfoFromTableGroup(STsdbReadHandle* pTsdbReadHandle, SArray* pTableList) {
  size_t tableSize = taosArrayGetSize(pTableList);

  // allocate buffer in order to load data blocks from file
  SArray* pTableCheckInfo = taosArrayInit(tableSize, sizeof(STableCheckInfo));
  if (pTableCheckInfo == NULL) {
    return NULL;
  }

  // todo apply the lastkey of table check to avoid to load header file
  for (int32_t j = 0; j < tableSize; ++j) {
    STableKeyInfo* pKeyInfo = (STableKeyInfo*)taosArrayGet(pTableList, j);

    STableCheckInfo info = {.lastKey = pKeyInfo->lastKey, .tableId = pKeyInfo->uid};
    info.suid = pTsdbReadHandle->suid;
    if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
      if (info.lastKey == INT64_MIN || info.lastKey < pTsdbReadHandle->window.skey) {
        info.lastKey = pTsdbReadHandle->window.skey;
      }

      assert(info.lastKey >= pTsdbReadHandle->window.skey && info.lastKey <= pTsdbReadHandle->window.ekey);
    } else {
      info.lastKey = pTsdbReadHandle->window.skey;
    }

    taosArrayPush(pTableCheckInfo, &info);
    tsdbDebug("%p check table uid:%" PRId64 " from lastKey:%" PRId64 " %s", pTsdbReadHandle, info.tableId, info.lastKey,
              pTsdbReadHandle->idStr);
  }

  return pTableCheckInfo;
}

static void resetCheckInfo(STsdbReadHandle* pTsdbReadHandle) {
  size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
  assert(numOfTables >= 1);

  // todo apply the lastkey of table check to avoid to load header file
  for (int32_t i = 0; i < numOfTables; ++i) {
    STableCheckInfo* pCheckInfo = (STableCheckInfo*)taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);
    pCheckInfo->lastKey = pTsdbReadHandle->window.skey;
    pCheckInfo->iter = tsdbTbDataIterDestroy(pCheckInfo->iter);
    pCheckInfo->iiter = tsdbTbDataIterDestroy(pCheckInfo->iiter);
    pCheckInfo->initBuf = false;

    if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
      assert(pCheckInfo->lastKey >= pTsdbReadHandle->window.skey);
    } else {
      assert(pCheckInfo->lastKey <= pTsdbReadHandle->window.skey);
    }
  }
}

// only one table, not need to sort again
static SArray* createCheckInfoFromCheckInfo(STableCheckInfo* pCheckInfo, TSKEY skey, SArray** psTable) {
  SArray* pNew = taosArrayInit(1, sizeof(STableCheckInfo));

  STableCheckInfo info = {.lastKey = skey};

  info.tableId = pCheckInfo->tableId;
  taosArrayPush(pNew, &info);
  return pNew;
}

static bool emptyQueryTimewindow(STsdbReadHandle* pTsdbReadHandle) {
  assert(pTsdbReadHandle != NULL);

  STimeWindow* w = &pTsdbReadHandle->window;
  bool         asc = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

  return ((asc && w->skey > w->ekey) || (!asc && w->ekey > w->skey));
}

// Update the query time window according to the data time to live(TTL) information, in order to avoid to return
// the expired data to client, even it is queried already.
static int64_t getEarliestValidTimestamp(STsdb* pTsdb) {
  STsdbKeepCfg* pCfg = REPO_KEEP_CFG(pTsdb);

  int64_t now = taosGetTimestamp(pCfg->precision);
  return now - (tsTickPerMin[pCfg->precision] * pCfg->keep2) + 1;  // needs to add one tick
}

static void setQueryTimewindow(STsdbReadHandle* pTsdbReadHandle, SQueryTableDataCond* pCond, int32_t tWinIdx) {
  pTsdbReadHandle->window = pCond->twindows[tWinIdx];

  bool    updateTs = false;
  int64_t startTs = getEarliestValidTimestamp(pTsdbReadHandle->pTsdb);
  if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
    if (startTs > pTsdbReadHandle->window.skey) {
      pTsdbReadHandle->window.skey = startTs;
      pCond->twindows[tWinIdx].skey = startTs;
      updateTs = true;
    }
  } else {
    if (startTs > pTsdbReadHandle->window.ekey) {
      pTsdbReadHandle->window.ekey = startTs;
      pCond->twindows[tWinIdx].ekey = startTs;
      updateTs = true;
    }
  }

  if (updateTs) {
    tsdbDebug("%p update the query time window, old:%" PRId64 " - %" PRId64 ", new:%" PRId64 " - %" PRId64 ", %s",
              pTsdbReadHandle, pCond->twindows[tWinIdx].skey, pCond->twindows[tWinIdx].ekey,
              pTsdbReadHandle->window.skey, pTsdbReadHandle->window.ekey, pTsdbReadHandle->idStr);
  }
}

static STsdb* getTsdbByRetentions(SVnode* pVnode, STsdbReadHandle* pReadHandle, TSKEY winSKey, SRetention* retentions) {
  if (VND_IS_RSMA(pVnode)) {
    int     level = 0;
    int64_t now = taosGetTimestamp(pVnode->config.tsdbCfg.precision);

    for (int i = 0; i < TSDB_RETENTION_MAX; ++i) {
      SRetention* pRetention = retentions + level;
      if (pRetention->keep <= 0) {
        if (level > 0) {
          --level;
        }
        break;
      }
      if ((now - pRetention->keep) <= winSKey) {
        break;
      }
      ++level;
    }

    if (level == TSDB_RETENTION_L0) {
      tsdbDebug("vgId:%d, read handle %p rsma level %d is selected to query", TD_VID(pVnode), pReadHandle,
                TSDB_RETENTION_L0);
      return VND_RSMA0(pVnode);
    } else if (level == TSDB_RETENTION_L1) {
      tsdbDebug("vgId:%d, read handle %p rsma level %d is selected to query", TD_VID(pVnode), pReadHandle,
                TSDB_RETENTION_L1);
      return VND_RSMA1(pVnode);
    } else {
      tsdbDebug("vgId:%d, read handle %p rsma level %d is selected to query", TD_VID(pVnode), pReadHandle,
                TSDB_RETENTION_L2);
      return VND_RSMA2(pVnode);
    }
  }
  return VND_TSDB(pVnode);
}

static STsdbReadHandle* tsdbQueryTablesImpl(SVnode* pVnode, SQueryTableDataCond* pCond, uint64_t qId, uint64_t taskId) {
  STsdbReadHandle* pReadHandle = taosMemoryCalloc(1, sizeof(STsdbReadHandle));
  if (pReadHandle == NULL) {
    goto _end;
  }

  STsdb* pTsdb = getTsdbByRetentions(pVnode, pReadHandle, pCond->twindows[0].skey, pVnode->config.tsdbCfg.retentions);

  pReadHandle->order = pCond->order;
  pReadHandle->pTsdb = pTsdb;
  pReadHandle->type = TSDB_QUERY_TYPE_ALL;
  pReadHandle->cur.fid = INT32_MIN;
  pReadHandle->cur.win = TSWINDOW_INITIALIZER;
  pReadHandle->checkFiles = true;
  pReadHandle->activeIndex = 0;  // current active table index
  pReadHandle->allocSize = 0;
  pReadHandle->locateStart = false;
  pReadHandle->loadType = pCond->type;

  pReadHandle->suid = pCond->suid;
  pReadHandle->outputCapacity = 4096;  //((STsdb*)tsdb)->config.maxRowsPerFileBlock;
  pReadHandle->loadExternalRow = pCond->loadExternalRows;
  pReadHandle->currentLoadExternalRows = pCond->loadExternalRows;

  char buf[128] = {0};
  snprintf(buf, tListLen(buf), "TID:0x%" PRIx64 " QID:0x%" PRIx64, taskId, qId);
  pReadHandle->idStr = strdup(buf);

  if (tsdbInitReadH(&pReadHandle->rhelper, pReadHandle->pTsdb) != 0) {
    goto _end;
  }

  assert(pCond != NULL);
  setQueryTimewindow(pReadHandle, pCond, 0);

  if (pCond->numOfCols > 0) {
    int32_t rowLen = 0;
    for (int32_t i = 0; i < pCond->numOfCols; ++i) {
      rowLen += pCond->colList[i].bytes;
    }

    // make sure the output SSDataBlock size be less than 2MB.
    int32_t TWOMB = 2 * 1024 * 1024;
    if (pReadHandle->outputCapacity * rowLen > TWOMB) {
      pReadHandle->outputCapacity = TWOMB / rowLen;
    }

    // allocate buffer in order to load data blocks from file
    pReadHandle->suppInfo.pstatis = taosMemoryCalloc(pCond->numOfCols, sizeof(SColumnDataAgg));
    if (pReadHandle->suppInfo.pstatis == NULL) {
      goto _end;
    }

    // todo: use list instead of array?
    pReadHandle->pResBlock = createDataBlock();
    if (pReadHandle->pResBlock == NULL) {
      goto _end;
    }

    for (int32_t i = 0; i < pCond->numOfCols; ++i) {
      SColumnInfoData colInfo = {.info = pCond->colList[i], 0};
      int32_t         code = blockDataAppendColInfo(pReadHandle->pResBlock, &colInfo);
      if (code != TSDB_CODE_SUCCESS) {
        goto _end;
      }
    }

    blockDataEnsureCapacity(pReadHandle->pResBlock, pReadHandle->outputCapacity);

    pReadHandle->suppInfo.defaultLoadColumn = getDefaultLoadColumns(pReadHandle, true);

    size_t size = taosArrayGetSize(pReadHandle->suppInfo.defaultLoadColumn);
    pReadHandle->suppInfo.slotIds = taosMemoryCalloc(size, sizeof(int32_t));
    pReadHandle->suppInfo.plist = taosMemoryCalloc(size, POINTER_BYTES);
  }

  pReadHandle->pDataCols = tdNewDataCols(1000, pVnode->config.tsdbCfg.maxRows);
  if (pReadHandle->pDataCols == NULL) {
    tsdbError("%p failed to malloc buf for pDataCols, %s", pReadHandle, pReadHandle->idStr);
    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
    goto _end;
  }

  tsdbInitDataBlockLoadInfo(&pReadHandle->dataBlockLoadInfo);
  tsdbInitCompBlockLoadInfo(&pReadHandle->compBlockLoadInfo);

  return (tsdbReaderT)pReadHandle;

_end:
  tsdbCleanupReadHandle(pReadHandle);
  terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
  return NULL;
}

static int32_t setCurrentSchema(SVnode* pVnode, STsdbReadHandle* pTsdbReadHandle) {
  STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, 0);

  int32_t sversion = 1;

  SMetaReader mr = {0};
  metaReaderInit(&mr, pVnode->pMeta, 0);
  int32_t code = metaGetTableEntryByUid(&mr, pCheckInfo->tableId);
  if (code != TSDB_CODE_SUCCESS) {
    terrno = TSDB_CODE_TDB_INVALID_TABLE_ID;
    metaReaderClear(&mr);
    return terrno;
  }

  if (mr.me.type == TSDB_CHILD_TABLE) {
    tb_uid_t suid = mr.me.ctbEntry.suid;
    code = metaGetTableEntryByUid(&mr, suid);
    if (code != TSDB_CODE_SUCCESS) {
      terrno = TSDB_CODE_TDB_INVALID_TABLE_ID;
      metaReaderClear(&mr);
      return terrno;
    }
    sversion = mr.me.stbEntry.schemaRow.version;
  } else {
    ASSERT(mr.me.type == TSDB_NORMAL_TABLE);
    sversion = mr.me.ntbEntry.schemaRow.version;
  }

  metaReaderClear(&mr);
  pTsdbReadHandle->pSchema = metaGetTbTSchema(pVnode->pMeta, pCheckInfo->tableId, sversion);
  return TSDB_CODE_SUCCESS;
}

int32_t tsdbSetTableId(tsdbReaderT reader, int64_t uid) {
  STsdbReadHandle* pTsdbReadHandle = reader;
  if (pTsdbReadHandle->pTableCheckInfo) taosArrayDestroy(pTsdbReadHandle->pTableCheckInfo);
  pTsdbReadHandle->pTableCheckInfo = createCheckInfoFromUid(pTsdbReadHandle, uid);
  if (pTsdbReadHandle->pTableCheckInfo == NULL) {
    return TSDB_CODE_TDB_OUT_OF_MEMORY;
  }
  return TDB_CODE_SUCCESS;
}

int32_t tsdbSetTableList(tsdbReaderT reader, SArray* tableList) {
  STsdbReadHandle* pTsdbReadHandle = reader;
  if (pTsdbReadHandle->pTableCheckInfo) taosArrayDestroy(pTsdbReadHandle->pTableCheckInfo);
  pTsdbReadHandle->pTableCheckInfo = createCheckInfoFromTableGroup(pTsdbReadHandle, tableList);
  if (pTsdbReadHandle->pTableCheckInfo == NULL) {
    return TSDB_CODE_TDB_OUT_OF_MEMORY;
  }
  return TDB_CODE_SUCCESS;
}

tsdbReaderT tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, SArray* tableList, uint64_t qId,
                           uint64_t taskId) {
  if (taosArrayGetSize(tableList) == 0) {
    return NULL;
  }
  STsdbReadHandle* pTsdbReadHandle = tsdbQueryTablesImpl(pVnode, pCond, qId, taskId);
  if (pTsdbReadHandle == NULL) {
    return NULL;
  }

  if (emptyQueryTimewindow(pTsdbReadHandle)) {
    return (tsdbReaderT)pTsdbReadHandle;
  }

  // todo apply the lastkey of table check to avoid to load header file
  pTsdbReadHandle->pTableCheckInfo = createCheckInfoFromTableGroup(pTsdbReadHandle, tableList);
  if (pTsdbReadHandle->pTableCheckInfo == NULL) {
    //    tsdbCleanupReadHandle(pTsdbReadHandle);
    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
    return NULL;
  }

  int32_t code = setCurrentSchema(pVnode, pTsdbReadHandle);
  if (code != TSDB_CODE_SUCCESS) {
    terrno = code;
    return NULL;
  }

  int32_t  numOfCols = taosArrayGetSize(pTsdbReadHandle->suppInfo.defaultLoadColumn);
  int16_t* ids = pTsdbReadHandle->suppInfo.defaultLoadColumn->pData;

  STSchema* pSchema = pTsdbReadHandle->pSchema;

  int32_t i = 0, j = 0;
  while (i < numOfCols && j < pSchema->numOfCols) {
    if (ids[i] == pSchema->columns[j].colId) {
      pTsdbReadHandle->suppInfo.slotIds[i] = j;
      i++;
      j++;
    } else if (ids[i] > pSchema->columns[j].colId) {
      j++;
    } else {
      //    tsdbCleanupReadHandle(pTsdbReadHandle);
      terrno = TSDB_CODE_INVALID_PARA;
      return NULL;
    }
  }

  tsdbDebug("%p total numOfTable:%" PRIzu " in this query, table %" PRIzu " %s", pTsdbReadHandle,
            taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo), taosArrayGetSize(tableList), pTsdbReadHandle->idStr);

  return (tsdbReaderT)pTsdbReadHandle;
}

void tsdbResetReadHandle(tsdbReaderT queryHandle, SQueryTableDataCond* pCond, int32_t tWinIdx) {
  STsdbReadHandle* pTsdbReadHandle = queryHandle;

  if (emptyQueryTimewindow(pTsdbReadHandle)) {
    if (pCond->order != pTsdbReadHandle->order) {
      pTsdbReadHandle->order = pCond->order;
      TSWAP(pTsdbReadHandle->window.skey, pTsdbReadHandle->window.ekey);
    }

    return;
  }

  pTsdbReadHandle->order = pCond->order;
  setQueryTimewindow(pTsdbReadHandle, pCond, tWinIdx);
  pTsdbReadHandle->type = TSDB_QUERY_TYPE_ALL;
  pTsdbReadHandle->cur.fid = -1;
  pTsdbReadHandle->cur.win = TSWINDOW_INITIALIZER;
  pTsdbReadHandle->checkFiles = true;
  pTsdbReadHandle->activeIndex = 0;  // current active table index
  pTsdbReadHandle->locateStart = false;
  pTsdbReadHandle->loadExternalRow = pCond->loadExternalRows;

  if (ASCENDING_TRAVERSE(pCond->order)) {
    assert(pTsdbReadHandle->window.skey <= pTsdbReadHandle->window.ekey);
  } else {
    assert(pTsdbReadHandle->window.skey >= pTsdbReadHandle->window.ekey);
  }

  // allocate buffer in order to load data blocks from file
  memset(pTsdbReadHandle->suppInfo.pstatis, 0, sizeof(SColumnDataAgg));
  memset(pTsdbReadHandle->suppInfo.plist, 0, POINTER_BYTES);

  tsdbInitDataBlockLoadInfo(&pTsdbReadHandle->dataBlockLoadInfo);
  tsdbInitCompBlockLoadInfo(&pTsdbReadHandle->compBlockLoadInfo);

  resetCheckInfo(pTsdbReadHandle);
}

void tsdbResetQueryHandleForNewTable(tsdbReaderT queryHandle, SQueryTableDataCond* pCond, STableListInfo* tableList,
                                     int32_t tWinIdx) {
  STsdbReadHandle* pTsdbReadHandle = queryHandle;

  pTsdbReadHandle->order = pCond->order;
  pTsdbReadHandle->window = pCond->twindows[tWinIdx];
  pTsdbReadHandle->type = TSDB_QUERY_TYPE_ALL;
  pTsdbReadHandle->cur.fid = -1;
  pTsdbReadHandle->cur.win = TSWINDOW_INITIALIZER;
  pTsdbReadHandle->checkFiles = true;
  pTsdbReadHandle->activeIndex = 0;  // current active table index
  pTsdbReadHandle->locateStart = false;
  pTsdbReadHandle->loadExternalRow = pCond->loadExternalRows;

  if (ASCENDING_TRAVERSE(pCond->order)) {
    assert(pTsdbReadHandle->window.skey <= pTsdbReadHandle->window.ekey);
  } else {
    assert(pTsdbReadHandle->window.skey >= pTsdbReadHandle->window.ekey);
  }

  // allocate buffer in order to load data blocks from file
  memset(pTsdbReadHandle->suppInfo.pstatis, 0, sizeof(SColumnDataAgg));
  memset(pTsdbReadHandle->suppInfo.plist, 0, POINTER_BYTES);

  tsdbInitDataBlockLoadInfo(&pTsdbReadHandle->dataBlockLoadInfo);
  tsdbInitCompBlockLoadInfo(&pTsdbReadHandle->compBlockLoadInfo);

  SArray* pTable = NULL;
  //  STsdbMeta* pMeta = tsdbGetMeta(pTsdbReadHandle->pTsdb);

  //  pTsdbReadHandle->pTableCheckInfo = destroyTableCheckInfo(pTsdbReadHandle->pTableCheckInfo);

  pTsdbReadHandle->pTableCheckInfo = NULL;  // createCheckInfoFromTableGroup(pTsdbReadHandle, groupList, pMeta,
                                            // &pTable);
  if (pTsdbReadHandle->pTableCheckInfo == NULL) {
    //    tsdbCleanupReadHandle(pTsdbReadHandle);
    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
  }

  //  pTsdbReadHandle->prev = doFreeColumnInfoData(pTsdbReadHandle->prev);
  //  pTsdbReadHandle->next = doFreeColumnInfoData(pTsdbReadHandle->next);
}

tsdbReaderT tsdbQueryLastRow(SVnode* pVnode, SQueryTableDataCond* pCond, STableListInfo* pList, uint64_t qId,
                             uint64_t taskId) {
  pCond->twindows[0] = updateLastrowForEachGroup(pList);

  // no qualified table
  if (taosArrayGetSize(pList->pTableList) == 0) {
    return NULL;
  }

  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)tsdbReaderOpen(pVnode, pCond, pList->pTableList, qId, taskId);
  if (pTsdbReadHandle == NULL) {
    return NULL;
  }

  int32_t code = checkForCachedLastRow(pTsdbReadHandle, pList);
  if (code != TSDB_CODE_SUCCESS) {  // set the numOfTables to be 0
    terrno = code;
    return NULL;
  }

  assert(pCond->order == TSDB_ORDER_ASC && pCond->twindows[0].skey <= pCond->twindows[0].ekey);
  if (pTsdbReadHandle->cachelastrow) {
    pTsdbReadHandle->type = TSDB_QUERY_TYPE_LAST;
  }

  return pTsdbReadHandle;
}

#if 0
tsdbReaderT tsdbQueryCacheLastT(STsdb *tsdb, SQueryTableDataCond *pCond, STableGroupInfo *groupList, uint64_t qId, SMemTable* pMemRef) {
  STsdbReadHandle *pTsdbReadHandle = (STsdbReadHandle*) tsdbQueryTablesT(tsdb, pCond, groupList, qId, pMemRef);
  if (pTsdbReadHandle == NULL) {
    return NULL;
  }

  int32_t code = checkForCachedLast(pTsdbReadHandle);
  if (code != TSDB_CODE_SUCCESS) { // set the numOfTables to be 0
    terrno = code;
    return NULL;
  }

  if (pTsdbReadHandle->cachelastrow) {
    pTsdbReadHandle->type = TSDB_QUERY_TYPE_LAST;
  }
  
  return pTsdbReadHandle;
}

#endif
SArray* tsdbGetQueriedTableList(tsdbReaderT* pHandle) {
  assert(pHandle != NULL);

  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)pHandle;

  size_t  size = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
  SArray* res = taosArrayInit(size, POINTER_BYTES);
  return res;
}

// leave only one table for each group
// static STableGroupInfo* trimTableGroup(STimeWindow* window, STableGroupInfo* pGroupList) {
//  assert(pGroupList);
//  size_t numOfGroup = taosArrayGetSize(pGroupList->pGroupList);
//
//  STableGroupInfo* pNew = taosMemoryCalloc(1, sizeof(STableGroupInfo));
//  pNew->pGroupList = taosArrayInit(numOfGroup, POINTER_BYTES);
//
//  for (int32_t i = 0; i < numOfGroup; ++i) {
//    SArray* oneGroup = taosArrayGetP(pGroupList->pGroupList, i);
//    size_t  numOfTables = taosArrayGetSize(oneGroup);
//
//    SArray* px = taosArrayInit(4, sizeof(STableKeyInfo));
//    for (int32_t j = 0; j < numOfTables; ++j) {
//      STableKeyInfo* pInfo = (STableKeyInfo*)taosArrayGet(oneGroup, j);
//      //      if (window->skey <= pInfo->lastKey && ((STable*)pInfo->pTable)->lastKey != TSKEY_INITIAL_VAL) {
//      //        taosArrayPush(px, pInfo);
//      //        pNew->numOfTables += 1;
//      //        break;
//      //      }
//    }
//
//    // there are no data in this group
//    if (taosArrayGetSize(px) == 0) {
//      taosArrayDestroy(px);
//    } else {
//      taosArrayPush(pNew->pGroupList, &px);
//    }
//  }
//
//  return pNew;
//}

// tsdbReaderT tsdbQueryRowsInExternalWindow(SVnode* pVnode, SQueryTableDataCond* pCond, STableGroupInfo* groupList,
//                                          uint64_t qId, uint64_t taskId) {
//  STableGroupInfo* pNew = trimTableGroup(&pCond->twindow, groupList);
//
//  if (pNew->numOfTables == 0) {
//    tsdbDebug("update query time range to invalidate time window");
//
//    assert(taosArrayGetSize(pNew->pGroupList) == 0);
//    bool asc = ASCENDING_TRAVERSE(pCond->order);
//    if (asc) {
//      pCond->twindow.ekey = pCond->twindow.skey - 1;
//    } else {
//      pCond->twindow.skey = pCond->twindow.ekey - 1;
//    }
//  }
//
//  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)tsdbQueryTables(pVnode, pCond, pNew, qId, taskId);
//  pTsdbReadHandle->loadExternalRow = true;
//  pTsdbReadHandle->currentLoadExternalRows = true;
//
//  return pTsdbReadHandle;
//}

static bool initTableMemIterator(STsdbReadHandle* pHandle, STableCheckInfo* pCheckInfo) {
  if (pCheckInfo->initBuf) {
    return true;
  }

  pCheckInfo->initBuf = true;
  int32_t order = pHandle->order;

  STbData* pMem = NULL;
  STbData* pIMem = NULL;
  int8_t   backward = (pHandle->order == TSDB_ORDER_DESC) ? 1 : 0;

  TSKEY tLastKey = keyToTkey(pCheckInfo->lastKey);
  if (pHandle->pTsdb->mem != NULL) {
    tsdbGetTbDataFromMemTable(pHandle->pTsdb->mem, pCheckInfo->suid, pCheckInfo->tableId, &pMem);
    if (pMem != NULL) {
      tsdbTbDataIterCreate(pMem, &(TSDBKEY){.version = 0, .ts = tLastKey}, backward, &pCheckInfo->iter);
    }
  }

  if (pHandle->pTsdb->imem != NULL) {
    tsdbGetTbDataFromMemTable(pHandle->pTsdb->mem, pCheckInfo->suid, pCheckInfo->tableId, &pIMem);
    if (pIMem != NULL) {
      tsdbTbDataIterCreate(pIMem, &(TSDBKEY){.version = 0, .ts = tLastKey}, backward, &pCheckInfo->iiter);
    }
  }

  // both iterators are NULL, no data in buffer right now
  if (pCheckInfo->iter == NULL && pCheckInfo->iiter == NULL) {
    return false;
  }

  bool memEmpty =
      (pCheckInfo->iter == NULL) || (pCheckInfo->iter != NULL && !tsdbTbDataIterGet(pCheckInfo->iter, NULL));
  bool imemEmpty =
      (pCheckInfo->iiter == NULL) || (pCheckInfo->iiter != NULL && !tsdbTbDataIterGet(pCheckInfo->iiter, NULL));
  if (memEmpty && imemEmpty) {  // buffer is empty
    return false;
  }

  if (!memEmpty) {
    TSDBROW row;

    tsdbTbDataIterGet(pCheckInfo->iter, &row);
    TSKEY key = row.pTSRow->ts;  // first timestamp in buffer
    tsdbDebug("%p uid:%" PRId64 ", check data in mem from skey:%" PRId64 ", order:%d, ts range in buf:%" PRId64
              "-%" PRId64 ", lastKey:%" PRId64 ", numOfRows:%" PRId64 ", %s",
              pHandle, pCheckInfo->tableId, key, order, pMem->minKey.ts, pMem->maxKey.ts, pCheckInfo->lastKey,
              pMem->sl.size, pHandle->idStr);

    if (ASCENDING_TRAVERSE(order)) {
      assert(pCheckInfo->lastKey <= key);
    } else {
      assert(pCheckInfo->lastKey >= key);
    }

  } else {
    tsdbDebug("%p uid:%" PRId64 ", no data in mem, %s", pHandle, pCheckInfo->tableId, pHandle->idStr);
  }

  if (!imemEmpty) {
    TSDBROW row;

    tsdbTbDataIterGet(pCheckInfo->iter, &row);
    TSKEY key = row.pTSRow->ts;  // first timestamp in buffer
    tsdbDebug("%p uid:%" PRId64 ", check data in imem from skey:%" PRId64 ", order:%d, ts range in buf:%" PRId64
              "-%" PRId64 ", lastKey:%" PRId64 ", numOfRows:%" PRId64 ", %s",
              pHandle, pCheckInfo->tableId, key, order, pIMem->minKey.ts, pIMem->maxKey.ts, pCheckInfo->lastKey,
              pIMem->sl.size, pHandle->idStr);

    if (ASCENDING_TRAVERSE(order)) {
      assert(pCheckInfo->lastKey <= key);
    } else {
      assert(pCheckInfo->lastKey >= key);
    }
  } else {
    tsdbDebug("%p uid:%" PRId64 ", no data in imem, %s", pHandle, pCheckInfo->tableId, pHandle->idStr);
  }

  return true;
}

static void destroyTableMemIterator(STableCheckInfo* pCheckInfo) {
  tsdbTbDataIterDestroy(pCheckInfo->iter);
  tsdbTbDataIterDestroy(pCheckInfo->iiter);
}

static TSKEY extractFirstTraverseKey(STableCheckInfo* pCheckInfo, int32_t order, int32_t update, TDRowVerT maxVer) {
  TSDBROW row = {0};
  STSRow *rmem = NULL, *rimem = NULL;

  if (pCheckInfo->iter) {
    if (tsdbTbDataIterGet(pCheckInfo->iter, &row)) {
      rmem = row.pTSRow;
    }
  }

  if (pCheckInfo->iiter) {
    if (tsdbTbDataIterGet(pCheckInfo->iiter, &row)) {
      rimem = row.pTSRow;
    }
  }

  if (rmem == NULL && rimem == NULL) {
    return TSKEY_INITIAL_VAL;
  }

  if (rmem != NULL && rimem == NULL) {
    pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
    return TD_ROW_KEY(rmem);
  }

  if (rmem == NULL && rimem != NULL) {
    pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
    return TD_ROW_KEY(rimem);
  }

  TSKEY r1 = TD_ROW_KEY(rmem);
  TSKEY r2 = TD_ROW_KEY(rimem);

  if (r1 == r2) {
#if 0
    if (update == TD_ROW_DISCARD_UPDATE) {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
      tSkipListIterNext(pCheckInfo->iter);
    } else if (update == TD_ROW_OVERWRITE_UPDATE) {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
      tSkipListIterNext(pCheckInfo->iiter);
    } else {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_BOTH;
    }
#endif
    if (TD_SUPPORT_UPDATE(update)) {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_BOTH;
    } else {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
      tsdbTbDataIterNext(pCheckInfo->iter);
    }
    return r1;
  } else if (r1 < r2 && ASCENDING_TRAVERSE(order)) {
    pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
    return r1;
  } else {
    pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
    return r2;
  }
}

static STSRow* getSRowInTableMem(STableCheckInfo* pCheckInfo, int32_t order, int32_t update, STSRow** extraRow,
                                 TDRowVerT maxVer) {
  TSDBROW row;
  STSRow *rmem = NULL, *rimem = NULL;
  if (pCheckInfo->iter) {
    if (tsdbTbDataIterGet(pCheckInfo->iter, &row)) {
      rmem = row.pTSRow;
    }
  }

  if (pCheckInfo->iiter) {
    if (tsdbTbDataIterGet(pCheckInfo->iiter, &row)) {
      rimem = row.pTSRow;
    }
  }

  if (rmem == NULL && rimem == NULL) {
    return NULL;
  }

  if (rmem != NULL && rimem == NULL) {
    pCheckInfo->chosen = 0;
    return rmem;
  }

  if (rmem == NULL && rimem != NULL) {
    pCheckInfo->chosen = 1;
    return rimem;
  }

  TSKEY r1 = TD_ROW_KEY(rmem);
  TSKEY r2 = TD_ROW_KEY(rimem);

  if (r1 == r2) {
#if 0
    if (update == TD_ROW_DISCARD_UPDATE) {
      tSkipListIterNext(pCheckInfo->iter);
      pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
      return rimem;
    } else if (update == TD_ROW_OVERWRITE_UPDATE) {
      tSkipListIterNext(pCheckInfo->iiter);
      pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
      return rmem;
    } else {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_BOTH;
      *extraRow = rimem;
      return rmem;
    }
#endif
    if (TD_SUPPORT_UPDATE(update)) {
      pCheckInfo->chosen = CHECKINFO_CHOSEN_BOTH;
      *extraRow = rimem;
      return rmem;
    } else {
      tsdbTbDataIterNext(pCheckInfo->iter);
      pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
      return rimem;
    }
  } else {
    if (ASCENDING_TRAVERSE(order)) {
      if (r1 < r2) {
        pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
        return rmem;
      } else {
        pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
        return rimem;
      }
    } else {
      if (r1 < r2) {
        pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
        return rimem;
      } else {
        pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
        return rmem;
      }
    }
  }
}

static bool moveToNextRowInMem(STableCheckInfo* pCheckInfo) {
  bool hasNext = false;
  if (pCheckInfo->chosen == CHECKINFO_CHOSEN_MEM) {
    if (pCheckInfo->iter != NULL) {
      hasNext = tsdbTbDataIterNext(pCheckInfo->iter);
    }

    if (hasNext) {
      return hasNext;
    }

    if (pCheckInfo->iiter != NULL) {
      return tsdbTbDataIterGet(pCheckInfo->iiter, NULL);
    }
  } else if (pCheckInfo->chosen == CHECKINFO_CHOSEN_IMEM) {
    if (pCheckInfo->iiter != NULL) {
      hasNext = tsdbTbDataIterNext(pCheckInfo->iiter);
    }

    if (hasNext) {
      return hasNext;
    }

    if (pCheckInfo->iter != NULL) {
      return tsdbTbDataIterGet(pCheckInfo->iter, NULL);
    }
  } else {
    if (pCheckInfo->iter != NULL) {
      hasNext = tsdbTbDataIterNext(pCheckInfo->iter);
    }
    if (pCheckInfo->iiter != NULL) {
      hasNext = tsdbTbDataIterNext(pCheckInfo->iiter) || hasNext;
    }
  }

  return hasNext;
}

static bool hasMoreDataInCache(STsdbReadHandle* pHandle) {
  STsdbCfg* pCfg = REPO_CFG(pHandle->pTsdb);
  size_t    size = taosArrayGetSize(pHandle->pTableCheckInfo);
  assert(pHandle->activeIndex < size && pHandle->activeIndex >= 0 && size >= 1);
  pHandle->cur.fid = INT32_MIN;

  STableCheckInfo* pCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
  if (!pCheckInfo->initBuf) {
    initTableMemIterator(pHandle, pCheckInfo);
  }

  STSRow* row = getSRowInTableMem(pCheckInfo, pHandle->order, pCfg->update, NULL, TD_VER_MAX);
  if (row == NULL) {
    return false;
  }

  pCheckInfo->lastKey = TD_ROW_KEY(row);  // first timestamp in buffer
  tsdbDebug("%p uid:%" PRId64 ", check data in buffer from skey:%" PRId64 ", order:%d, %s", pHandle,
            pCheckInfo->tableId, pCheckInfo->lastKey, pHandle->order, pHandle->idStr);

  // all data in mem are checked already.
  if ((pCheckInfo->lastKey > pHandle->window.ekey && ASCENDING_TRAVERSE(pHandle->order)) ||
      (pCheckInfo->lastKey < pHandle->window.ekey && !ASCENDING_TRAVERSE(pHandle->order))) {
    return false;
  }

  int32_t      step = ASCENDING_TRAVERSE(pHandle->order) ? 1 : -1;
  STimeWindow* win = &pHandle->cur.win;
  pHandle->cur.rows = tsdbReadRowsFromCache(pCheckInfo, pHandle->window.ekey, pHandle->outputCapacity, win, pHandle);

  // update the last key value
  pCheckInfo->lastKey = win->ekey + step;
  pHandle->cur.lastKey = win->ekey + step;
  pHandle->cur.mixBlock = true;

  if (!ASCENDING_TRAVERSE(pHandle->order)) {
    TSWAP(win->skey, win->ekey);
  }

  return true;
}

static int32_t getFileIdFromKey(TSKEY key, int32_t daysPerFile, int32_t precision) {
  assert(precision >= TSDB_TIME_PRECISION_MICRO || precision <= TSDB_TIME_PRECISION_NANO);
  if (key == TSKEY_INITIAL_VAL) {
    return INT32_MIN;
  }

  if (key < 0) {
    key -= (daysPerFile * tsTickPerMin[precision]);
  }

  int64_t fid = (int64_t)(key / (daysPerFile * tsTickPerMin[precision]));  // set the starting fileId
  if (fid < 0LL && llabs(fid) > INT32_MAX) {                               // data value overflow for INT32
    fid = INT32_MIN;
  }

  if (fid > 0LL && fid > INT32_MAX) {
    fid = INT32_MAX;
  }

  return (int32_t)fid;
}

static int32_t binarySearchForBlock(SBlock* pBlock, int32_t numOfBlocks, TSKEY skey, int32_t order) {
  int32_t firstSlot = 0;
  int32_t lastSlot = numOfBlocks - 1;

  int32_t midSlot = firstSlot;

  while (1) {
    numOfBlocks = lastSlot - firstSlot + 1;
    midSlot = (firstSlot + (numOfBlocks >> 1));

    if (numOfBlocks == 1) break;

    if (skey > pBlock[midSlot].maxKey.ts) {
      if (numOfBlocks == 2) break;
      if ((order == TSDB_ORDER_DESC) && (skey < pBlock[midSlot + 1].minKey.ts)) break;
      firstSlot = midSlot + 1;
    } else if (skey < pBlock[midSlot].minKey.ts) {
      if ((order == TSDB_ORDER_ASC) && (skey > pBlock[midSlot - 1].maxKey.ts)) break;
      lastSlot = midSlot - 1;
    } else {
      break;  // got the slot
    }
  }

  return midSlot;
}

static int32_t loadBlockInfo(STsdbReadHandle* pTsdbReadHandle, int32_t index, int32_t* numOfBlocks) {
  int32_t code = 0;

  STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, index);
  pCheckInfo->numOfBlocks = 0;

  STable table = {.uid = pCheckInfo->tableId, .suid = pCheckInfo->suid};
  table.pSchema = pTsdbReadHandle->pSchema;

  if (tsdbSetReadTable(&pTsdbReadHandle->rhelper, &table) != TSDB_CODE_SUCCESS) {
    code = terrno;
    return code;
  }

  SBlockIdx* compIndex = pTsdbReadHandle->rhelper.pBlkIdx;

  // no data block in this file, try next file
  if (compIndex == NULL || compIndex->uid != pCheckInfo->tableId) {
    return 0;  // no data blocks in the file belongs to pCheckInfo->pTable
  }

  if (pCheckInfo->compSize < (int32_t)compIndex->len) {
    assert(compIndex->len > 0);

    char* t = taosMemoryRealloc(pCheckInfo->pCompInfo, compIndex->len);
    if (t == NULL) {
      terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
      code = TSDB_CODE_TDB_OUT_OF_MEMORY;
      return code;
    }

    pCheckInfo->pCompInfo = (SBlockInfo*)t;
    pCheckInfo->compSize = compIndex->len;
  }

  if (tsdbLoadBlockInfo(&(pTsdbReadHandle->rhelper), (void*)(pCheckInfo->pCompInfo)) < 0) {
    return terrno;
  }
  SBlockInfo* pCompInfo = pCheckInfo->pCompInfo;

  TSKEY s = TSKEY_INITIAL_VAL, e = TSKEY_INITIAL_VAL;

  if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
    assert(pCheckInfo->lastKey <= pTsdbReadHandle->window.ekey &&
           pTsdbReadHandle->window.skey <= pTsdbReadHandle->window.ekey);
  } else {
    assert(pCheckInfo->lastKey >= pTsdbReadHandle->window.ekey &&
           pTsdbReadHandle->window.skey >= pTsdbReadHandle->window.ekey);
  }

  s = TMIN(pCheckInfo->lastKey, pTsdbReadHandle->window.ekey);
  e = TMAX(pCheckInfo->lastKey, pTsdbReadHandle->window.ekey);

  // discard the unqualified data block based on the query time window
  int32_t start = binarySearchForBlock(pCompInfo->blocks, compIndex->numOfBlocks, s, TSDB_ORDER_ASC);
  int32_t end = start;

  if (s > pCompInfo->blocks[start].maxKey.ts) {
    return 0;
  }

  // todo speedup the procedure of located end block
  while (end < (int32_t)compIndex->numOfBlocks && (pCompInfo->blocks[end].minKey.ts <= e)) {
    end += 1;
  }

  pCheckInfo->numOfBlocks = (end - start);

  if (start > 0) {
    memmove(pCompInfo->blocks, &pCompInfo->blocks[start], pCheckInfo->numOfBlocks * sizeof(SBlock));
  }

  (*numOfBlocks) += pCheckInfo->numOfBlocks;
  return 0;
}

static int32_t getFileCompInfo(STsdbReadHandle* pTsdbReadHandle, int32_t* numOfBlocks) {
  // load all the comp offset value for all tables in this file
  int32_t code = TSDB_CODE_SUCCESS;
  *numOfBlocks = 0;

  pTsdbReadHandle->cost.headFileLoad += 1;
  int64_t s = taosGetTimestampUs();

  size_t numOfTables = 0;
  if (pTsdbReadHandle->loadType == BLOCK_LOAD_TABLE_SEQ_ORDER) {
    code = loadBlockInfo(pTsdbReadHandle, pTsdbReadHandle->activeIndex, numOfBlocks);
  } else if (pTsdbReadHandle->loadType == BLOCK_LOAD_OFFSET_SEQ_ORDER) {
    numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

    for (int32_t i = 0; i < numOfTables; ++i) {
      code = loadBlockInfo(pTsdbReadHandle, i, numOfBlocks);
      if (code != TSDB_CODE_SUCCESS) {
        int64_t e = taosGetTimestampUs();

        pTsdbReadHandle->cost.headFileLoadTime += (e - s);
        return code;
      }
    }
  } else {
    assert(0);
  }

  int64_t e = taosGetTimestampUs();
  pTsdbReadHandle->cost.headFileLoadTime += (e - s);
  return code;
}

static int32_t doLoadFileDataBlock(STsdbReadHandle* pTsdbReadHandle, SBlock* pBlock, STableCheckInfo* pCheckInfo,
                                   int32_t slotIndex) {
  int64_t st = taosGetTimestampUs();

  int32_t code = tdInitDataCols(pTsdbReadHandle->pDataCols, pTsdbReadHandle->pSchema);
  if (code != TSDB_CODE_SUCCESS) {
    tsdbError("%p failed to malloc buf for pDataCols, %s", pTsdbReadHandle, pTsdbReadHandle->idStr);
    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
    goto _error;
  }

  code = tdInitDataCols(pTsdbReadHandle->rhelper.pDCols[0], pTsdbReadHandle->pSchema);
  if (code != TSDB_CODE_SUCCESS) {
    tsdbError("%p failed to malloc buf for rhelper.pDataCols[0], %s", pTsdbReadHandle, pTsdbReadHandle->idStr);
    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
    goto _error;
  }

  code = tdInitDataCols(pTsdbReadHandle->rhelper.pDCols[1], pTsdbReadHandle->pSchema);
  if (code != TSDB_CODE_SUCCESS) {
    tsdbError("%p failed to malloc buf for rhelper.pDataCols[1], %s", pTsdbReadHandle, pTsdbReadHandle->idStr);
    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
    goto _error;
  }

  int16_t* colIds = pTsdbReadHandle->suppInfo.defaultLoadColumn->pData;

  int32_t ret = tsdbLoadBlockDataCols(&(pTsdbReadHandle->rhelper), pBlock, pCheckInfo->pCompInfo, colIds,
                                      (int)(QH_GET_NUM_OF_COLS(pTsdbReadHandle)), true);
  if (ret != TSDB_CODE_SUCCESS) {
    int32_t c = terrno;
    assert(c != TSDB_CODE_SUCCESS);
    goto _error;
  }

  SDataBlockLoadInfo* pBlockLoadInfo = &pTsdbReadHandle->dataBlockLoadInfo;

  pBlockLoadInfo->fileGroup = pTsdbReadHandle->pFileGroup;
  pBlockLoadInfo->slot = pTsdbReadHandle->cur.slot;
  pBlockLoadInfo->uid = pCheckInfo->tableId;

  SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
  assert(pCols->numOfRows != 0 && pCols->numOfRows <= pBlock->numOfRows);

  pBlock->numOfRows = pCols->numOfRows;

  // Convert from TKEY to TSKEY for primary timestamp column if current block has timestamp before 1970-01-01T00:00:00Z
  if (pBlock->minKey.ts < 0 && colIds[0] == PRIMARYKEY_TIMESTAMP_COL_ID) {
    int64_t* src = pCols->cols[0].pData;
    for (int32_t i = 0; i < pBlock->numOfRows; ++i) {
      src[i] = tdGetKey(src[i]);
    }
  }

  int64_t elapsedTime = (taosGetTimestampUs() - st);
  pTsdbReadHandle->cost.blockLoadTime += elapsedTime;

  tsdbDebug("%p load file block into buffer, index:%d, brange:%" PRId64 "-%" PRId64 ", rows:%d, elapsed time:%" PRId64
            " us, %s",
            pTsdbReadHandle, slotIndex, pBlock->minKey.ts, pBlock->maxKey.ts, pBlock->numOfRows, elapsedTime,
            pTsdbReadHandle->idStr);
  return TSDB_CODE_SUCCESS;

_error:
  pBlock->numOfRows = 0;

  tsdbError("%p error occurs in loading file block, index:%d, brange:%" PRId64 "-%" PRId64 ", rows:%d, %s",
            pTsdbReadHandle, slotIndex, pBlock->minKey.ts, pBlock->maxKey.ts, pBlock->numOfRows,
            pTsdbReadHandle->idStr);
  return terrno;
}

static int32_t getEndPosInDataBlock(STsdbReadHandle* pTsdbReadHandle, SDataBlockInfo* pBlockInfo);
static int32_t doCopyRowsFromFileBlock(STsdbReadHandle* pTsdbReadHandle, int32_t capacity, int32_t numOfRows,
                                       int32_t start, int32_t end);
static void    doCheckGeneratedBlockRange(STsdbReadHandle* pTsdbReadHandle);
static void    copyAllRemainRowsFromFileBlock(STsdbReadHandle* pTsdbReadHandle, STableCheckInfo* pCheckInfo,
                                              SDataBlockInfo* pBlockInfo, int32_t endPos);

static int32_t handleDataMergeIfNeeded(STsdbReadHandle* pTsdbReadHandle, SBlock* pBlock, STableCheckInfo* pCheckInfo) {
  SQueryFilePos* cur = &pTsdbReadHandle->cur;
  STsdbCfg*      pCfg = REPO_CFG(pTsdbReadHandle->pTsdb);
  SDataBlockInfo binfo = GET_FILE_DATA_BLOCK_INFO(pCheckInfo, pBlock);
  TSKEY          key;
  int32_t        code = TSDB_CODE_SUCCESS;

  /*bool hasData = */ initTableMemIterator(pTsdbReadHandle, pCheckInfo);
  assert(cur->pos >= 0 && cur->pos <= binfo.rows);

  key = extractFirstTraverseKey(pCheckInfo, pTsdbReadHandle->order, pCfg->update, TD_VER_MAX);

  if (key != TSKEY_INITIAL_VAL) {
    tsdbDebug("%p key in mem:%" PRId64 ", %s", pTsdbReadHandle, key, pTsdbReadHandle->idStr);
  } else {
    tsdbDebug("%p no data in mem, %s", pTsdbReadHandle, pTsdbReadHandle->idStr);
  }

  bool ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

  if ((ascScan && (key != TSKEY_INITIAL_VAL && key <= binfo.window.ekey)) ||
      (!ascScan && (key != TSKEY_INITIAL_VAL && key >= binfo.window.skey))) {
    bool cacheDataInFileBlockHole = (ascScan && (key != TSKEY_INITIAL_VAL && key < binfo.window.skey)) ||
                                    (!ascScan && (key != TSKEY_INITIAL_VAL && key > binfo.window.ekey));
    if (cacheDataInFileBlockHole) {
      // do not load file block into buffer
      int32_t step = ascScan ? 1 : -1;

      TSKEY maxKey = ascScan ? (binfo.window.skey - step) : (binfo.window.ekey - step);
      cur->rows =
          tsdbReadRowsFromCache(pCheckInfo, maxKey, pTsdbReadHandle->outputCapacity, &cur->win, pTsdbReadHandle);
      pTsdbReadHandle->realNumOfRows = cur->rows;

      // update the last key value
      pCheckInfo->lastKey = cur->win.ekey + step;

      if (!ascScan) {
        TSWAP(cur->win.skey, cur->win.ekey);
      }

      cur->mixBlock = true;
      cur->blockCompleted = false;
      return code;
    }

    // return error, add test cases
    if ((code = doLoadFileDataBlock(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
      return code;
    }

    doMergeTwoLevelData(pTsdbReadHandle, pCheckInfo, pBlock);
  } else {
    /*
     * no data in cache, only load data from file
     * during the query processing, data in cache will not be checked anymore.
     * Here the buffer is not enough, so only part of file block can be loaded into memory buffer
     */
    int32_t endPos = getEndPosInDataBlock(pTsdbReadHandle, &binfo);

    bool wholeBlockReturned = ((abs(cur->pos - endPos) + 1) == binfo.rows);
    if (wholeBlockReturned) {
      pTsdbReadHandle->realNumOfRows = binfo.rows;

      cur->rows = binfo.rows;
      cur->win = binfo.window;
      cur->mixBlock = false;
      cur->blockCompleted = true;

      if (ascScan) {
        cur->lastKey = binfo.window.ekey + 1;
        cur->pos = binfo.rows;
      } else {
        cur->lastKey = binfo.window.skey - 1;
        cur->pos = -1;
      }
    } else {  // partially copy to dest buffer
      // make sure to only load once
      bool firstTimeExtract = ((cur->pos == 0 && ascScan) || (cur->pos == binfo.rows - 1 && (!ascScan)));
      if (pTsdbReadHandle->outputCapacity < binfo.rows && firstTimeExtract) {
        code = doLoadFileDataBlock(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot);
        if (code != TSDB_CODE_SUCCESS) {
          return code;
        }
      }

      copyAllRemainRowsFromFileBlock(pTsdbReadHandle, pCheckInfo, &binfo, endPos);
      cur->mixBlock = true;
    }

    if (pTsdbReadHandle->outputCapacity >= binfo.rows) {
      ASSERT(cur->blockCompleted || cur->mixBlock);
    }

    if (cur->rows == binfo.rows) {
      tsdbDebug("%p whole file block qualified, brange:%" PRId64 "-%" PRId64 ", rows:%d, lastKey:%" PRId64 ", %s",
                pTsdbReadHandle, cur->win.skey, cur->win.ekey, cur->rows, cur->lastKey, pTsdbReadHandle->idStr);
    } else {
      tsdbDebug("%p create data block from remain file block, brange:%" PRId64 "-%" PRId64
                ", rows:%d, total:%d, lastKey:%" PRId64 ", %s",
                pTsdbReadHandle, cur->win.skey, cur->win.ekey, cur->rows, binfo.rows, cur->lastKey,
                pTsdbReadHandle->idStr);
    }
  }

  return code;
}

static int32_t binarySearchForKey(char* pValue, int num, TSKEY key, int order);

static int32_t loadFileDataBlock(STsdbReadHandle* pTsdbReadHandle, SBlock* pBlock, STableCheckInfo* pCheckInfo,
                                 bool* exists) {
  SQueryFilePos* cur = &pTsdbReadHandle->cur;
  int32_t        code = TSDB_CODE_SUCCESS;
  bool           asc = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

  if (asc) {
    // query ended in/started from current block
    if (pTsdbReadHandle->window.ekey < pBlock->maxKey.ts || pCheckInfo->lastKey > pBlock->minKey.ts) {
      if ((code = doLoadFileDataBlock(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
        *exists = false;
        return code;
      }

      SDataCols* pTSCol = pTsdbReadHandle->rhelper.pDCols[0];
      assert(pTSCol->cols->type == TSDB_DATA_TYPE_TIMESTAMP && pTSCol->numOfRows == pBlock->numOfRows);

      if (pCheckInfo->lastKey > pBlock->minKey.ts) {
        cur->pos =
            binarySearchForKey(pTSCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey, pTsdbReadHandle->order);
      } else {
        cur->pos = 0;
      }

      assert(pCheckInfo->lastKey <= pBlock->maxKey.ts);
      doMergeTwoLevelData(pTsdbReadHandle, pCheckInfo, pBlock);
    } else {  // the whole block is loaded in to buffer
      cur->pos = asc ? 0 : (pBlock->numOfRows - 1);
      code = handleDataMergeIfNeeded(pTsdbReadHandle, pBlock, pCheckInfo);
    }
  } else {  // desc order, query ended in current block
    if (pTsdbReadHandle->window.ekey > pBlock->minKey.ts || pCheckInfo->lastKey < pBlock->maxKey.ts) {
      if ((code = doLoadFileDataBlock(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
        *exists = false;
        return code;
      }

      SDataCols* pTsCol = pTsdbReadHandle->rhelper.pDCols[0];
      if (pCheckInfo->lastKey < pBlock->maxKey.ts) {
        cur->pos =
            binarySearchForKey(pTsCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey, pTsdbReadHandle->order);
      } else {
        cur->pos = pBlock->numOfRows - 1;
      }

      assert(pCheckInfo->lastKey >= pBlock->minKey.ts);
      doMergeTwoLevelData(pTsdbReadHandle, pCheckInfo, pBlock);
    } else {
      cur->pos = asc ? 0 : (pBlock->numOfRows - 1);
      code = handleDataMergeIfNeeded(pTsdbReadHandle, pBlock, pCheckInfo);
    }
  }

  *exists = pTsdbReadHandle->realNumOfRows > 0;
  return code;
}

static int doBinarySearchKey(char* pValue, int num, TSKEY key, int order) {
  int    firstPos, lastPos, midPos = -1;
  int    numOfRows;
  TSKEY* keyList;

  assert(order == TSDB_ORDER_ASC || order == TSDB_ORDER_DESC);

  if (num <= 0) return -1;

  keyList = (TSKEY*)pValue;
  firstPos = 0;
  lastPos = num - 1;

  if (order == TSDB_ORDER_DESC) {
    // find the first position which is smaller than the key
    while (1) {
      if (key >= keyList[lastPos]) return lastPos;
      if (key == keyList[firstPos]) return firstPos;
      if (key < keyList[firstPos]) return firstPos - 1;

      numOfRows = lastPos - firstPos + 1;
      midPos = (numOfRows >> 1) + firstPos;

      if (key < keyList[midPos]) {
        lastPos = midPos - 1;
      } else if (key > keyList[midPos]) {
        firstPos = midPos + 1;
      } else {
        break;
      }
    }

  } else {
    // find the first position which is bigger than the key
    while (1) {
      if (key <= keyList[firstPos]) return firstPos;
      if (key == keyList[lastPos]) return lastPos;

      if (key > keyList[lastPos]) {
        lastPos = lastPos + 1;
        if (lastPos >= num)
          return -1;
        else
          return lastPos;
      }

      numOfRows = lastPos - firstPos + 1;
      midPos = (numOfRows >> 1) + firstPos;

      if (key < keyList[midPos]) {
        lastPos = midPos - 1;
      } else if (key > keyList[midPos]) {
        firstPos = midPos + 1;
      } else {
        break;
      }
    }
  }

  return midPos;
}

static int32_t doCopyRowsFromFileBlock(STsdbReadHandle* pTsdbReadHandle, int32_t capacity, int32_t numOfRows,
                                       int32_t start, int32_t end) {
  SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
  TSKEY*     tsArray = pCols->cols[0].pData;

  int32_t num = end - start + 1;
  assert(num >= 0);

  if (num == 0) {
    return numOfRows;
  }

  bool    ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);
  int32_t trueStart = ascScan ? start : end;
  int32_t trueEnd = ascScan ? end : start;
  int32_t step = ascScan ? 1 : -1;

  int32_t requiredNumOfCols = (int32_t)taosArrayGetSize(pTsdbReadHandle->pResBlock->pDataBlock);

  // data in buffer has greater timestamp, copy data in file block
  int32_t i = 0, j = 0;
  while (i < requiredNumOfCols && j < pCols->numOfCols) {
    SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);

    SDataCol* src = &pCols->cols[j];
    if (src->colId < pColInfo->info.colId) {
      j++;
      continue;
    }

    if (!isAllRowsNull(src) && pColInfo->info.colId == src->colId) {
      if (!IS_VAR_DATA_TYPE(pColInfo->info.type)) {  // todo opt performance
        //        memmove(pData, (char*)src->pData + bytes * start, bytes * num);
        int32_t rowIndex = numOfRows;
        for (int32_t k = trueStart; ((ascScan && k <= trueEnd) || (!ascScan && k >= trueEnd)); k += step, ++rowIndex) {
          SCellVal sVal = {0};
          if (tdGetColDataOfRow(&sVal, src, k, pCols->bitmapMode) < 0) {
            TASSERT(0);
          }

          if (sVal.valType == TD_VTYPE_NORM) {
            colDataAppend(pColInfo, rowIndex, sVal.val, false);
          } else {
            colDataAppendNULL(pColInfo, rowIndex);
          }
        }
      } else {  // handle the var-string
        int32_t rowIndex = numOfRows;

        // todo refactor, only copy one-by-one
        for (int32_t k = trueStart; ((ascScan && k <= trueEnd) || (!ascScan && k >= trueEnd)); k += step, ++rowIndex) {
          SCellVal sVal = {0};
          if (tdGetColDataOfRow(&sVal, src, k, pCols->bitmapMode) < 0) {
            TASSERT(0);
          }

          if (sVal.valType == TD_VTYPE_NORM) {
            colDataAppend(pColInfo, rowIndex, sVal.val, false);
          } else {
            colDataAppendNULL(pColInfo, rowIndex);
          }
        }
      }

      j++;
      i++;
    } else {  // pColInfo->info.colId < src->colId, it is a NULL data
      colDataAppendNNULL(pColInfo, numOfRows, num);
      i++;
    }
  }

  while (i < requiredNumOfCols) {  // the remain columns are all null data
    SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
    colDataAppendNNULL(pColInfo, numOfRows, num);
    i++;
  }

  pTsdbReadHandle->cur.win.ekey = tsArray[trueEnd];
  pTsdbReadHandle->cur.lastKey = tsArray[trueEnd] + step;

  return numOfRows + num;
}

/**
 * @brief  // TODO fix bug for reverse copy data problem
 *        Note: row1 always has high priority
 *
 * @param pTsdbReadHandle
 * @param capacity
 * @param curRow
 * @param row1
 * @param row2
 * @param numOfCols
 * @param uid
 * @param pSchema1
 * @param pSchema2
 * @param update
 * @param lastRowKey
 * @return int32_t The quantity of rows appended
 */
static int32_t mergeTwoRowFromMem(STsdbReadHandle* pTsdbReadHandle, int32_t capacity, int32_t* curRow, STSRow* row1,
                                  STSRow* row2, int32_t numOfCols, uint64_t uid, STSchema* pSchema1, STSchema* pSchema2,
                                  bool update, TSKEY* lastRowKey) {
#if 1
  STSchema* pSchema;
  STSRow*   row;
  int16_t   colId;
  int16_t   offset;

  bool     isRow1DataRow = TD_IS_TP_ROW(row1);
  bool     isRow2DataRow;
  bool     isChosenRowDataRow;
  int32_t  chosen_itr;
  SCellVal sVal = {0};
  TSKEY    rowKey = TSKEY_INITIAL_VAL;
  int32_t  nResult = 0;
  int32_t  mergeOption = 0;  // 0 discard 1 overwrite 2 merge

  // the schema version info is embeded in STSRow
  int32_t numOfColsOfRow1 = 0;

  if (pSchema1 == NULL) {
    pSchema1 = metaGetTbTSchema(REPO_META(pTsdbReadHandle->pTsdb), uid, TD_ROW_SVER(row1));
  }

#ifdef TD_DEBUG_PRINT_ROW
  char   flags[70] = {0};
  STsdb* pTsdb = pTsdbReadHandle->rhelper.pRepo;
  snprintf(flags, 70, "%s:%d vgId:%d dir:%s row1%s=NULL,row2%s=NULL", __func__, __LINE__, TD_VID(pTsdb->pVnode),
           pTsdb->dir, row1 ? "!" : "", row2 ? "!" : "");
  tdSRowPrint(row1, pSchema1, flags);
#endif

  if (isRow1DataRow) {
    numOfColsOfRow1 = schemaNCols(pSchema1);
  } else {
    numOfColsOfRow1 = tdRowGetNCols(row1);
  }

  int32_t numOfColsOfRow2 = 0;
  if (row2) {
    isRow2DataRow = TD_IS_TP_ROW(row2);
    if (pSchema2 == NULL) {
      pSchema2 = metaGetTbTSchema(REPO_META(pTsdbReadHandle->pTsdb), uid, TD_ROW_SVER(row2));
    }
    if (isRow2DataRow) {
      numOfColsOfRow2 = schemaNCols(pSchema2);
    } else {
      numOfColsOfRow2 = tdRowGetNCols(row2);
    }
  }

  int32_t i = 0, j = 0, k = 0;
  while (i < numOfCols && (j < numOfColsOfRow1 || k < numOfColsOfRow2)) {
    SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);

    int32_t colIdOfRow1;
    if (j >= numOfColsOfRow1) {
      colIdOfRow1 = INT32_MAX;
    } else if (isRow1DataRow) {
      colIdOfRow1 = pSchema1->columns[j].colId;
    } else {
      colIdOfRow1 = tdKvRowColIdAt(row1, j);
    }

    int32_t colIdOfRow2;
    if (k >= numOfColsOfRow2) {
      colIdOfRow2 = INT32_MAX;
    } else if (isRow2DataRow) {
      colIdOfRow2 = pSchema2->columns[k].colId;
    } else {
      colIdOfRow2 = tdKvRowColIdAt(row2, k);
    }

    if (colIdOfRow1 < colIdOfRow2) {  // the most probability
      if (colIdOfRow1 < pColInfo->info.colId) {
        ++j;
        continue;
      }
      row = row1;
      pSchema = pSchema1;
      isChosenRowDataRow = isRow1DataRow;
      chosen_itr = j;
    } else if (colIdOfRow1 == colIdOfRow2) {
      if (colIdOfRow1 < pColInfo->info.colId) {
        ++j;
        ++k;
        continue;
      }
      row = row1;
      pSchema = pSchema1;
      isChosenRowDataRow = isRow1DataRow;
      chosen_itr = j;
    } else {
      if (colIdOfRow2 < pColInfo->info.colId) {
        ++k;
        continue;
      }
      row = row2;
      pSchema = pSchema2;
      chosen_itr = k;
      isChosenRowDataRow = isRow2DataRow;
    }

    if (isChosenRowDataRow) {
      colId = pSchema->columns[chosen_itr].colId;
      offset = pSchema->columns[chosen_itr].offset;
      // TODO: use STSRowIter
      tdSTpRowGetVal(row, colId, pSchema->columns[chosen_itr].type, pSchema->flen, offset, chosen_itr - 1, &sVal);
      if (colId == PRIMARYKEY_TIMESTAMP_COL_ID) {
        rowKey = *(TSKEY*)sVal.val;
        if (rowKey != *lastRowKey) {
          mergeOption = 1;
          if (*lastRowKey != TSKEY_INITIAL_VAL) {
            ++(*curRow);
          }
          *lastRowKey = rowKey;
          ++nResult;
        } else if (update) {
          mergeOption = 2;
        } else {
          mergeOption = 0;
          break;
        }
      }
    } else {
      // TODO: use STSRowIter
      if (chosen_itr == 0) {
        colId = PRIMARYKEY_TIMESTAMP_COL_ID;
        tdSKvRowGetVal(row, PRIMARYKEY_TIMESTAMP_COL_ID, -1, -1, &sVal);
        rowKey = *(TSKEY*)sVal.val;
        if (rowKey != *lastRowKey) {
          mergeOption = 1;
          if (*lastRowKey != TSKEY_INITIAL_VAL) {
            ++(*curRow);
          }
          *lastRowKey = rowKey;
          ++nResult;
        } else if (update) {
          mergeOption = 2;
        } else {
          mergeOption = 0;
          break;
        }
      } else {
        SKvRowIdx* pColIdx = tdKvRowColIdxAt(row, chosen_itr - 1);
        colId = pColIdx->colId;
        offset = pColIdx->offset;
        tdSKvRowGetVal(row, colId, offset, chosen_itr - 1, &sVal);
      }
    }

    ASSERT(rowKey != TSKEY_INITIAL_VAL);

    if (colId == pColInfo->info.colId) {
      if (tdValTypeIsNorm(sVal.valType)) {
        colDataAppend(pColInfo, *curRow, sVal.val, false);
      } else if (tdValTypeIsNull(sVal.valType)) {
        colDataAppend(pColInfo, *curRow, NULL, true);
      } else if (tdValTypeIsNone(sVal.valType)) {
        // TODO: Set null if nothing append for this row
        if (mergeOption == 1) {
          colDataAppend(pColInfo, *curRow, NULL, true);
        }
      } else {
        ASSERT(0);
      }

      ++i;

      if (row == row1) {
        ++j;
      } else {
        ++k;
      }
    } else {
      if (mergeOption == 1) {
        colDataAppend(pColInfo, *curRow, NULL, true);
      }
      ++i;
    }
  }

  if (mergeOption == 1) {
    while (i < numOfCols) {  // the remain columns are all null data
      SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
      colDataAppend(pColInfo, *curRow, NULL, true);
      ++i;
    }
  }

  return nResult;
#endif
}

static void getQualifiedRowsPos(STsdbReadHandle* pTsdbReadHandle, int32_t startPos, int32_t endPos,
                                int32_t numOfExisted, int32_t* start, int32_t* end) {
  *start = -1;

  if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
    int32_t remain = endPos - startPos + 1;
    if (remain + numOfExisted > pTsdbReadHandle->outputCapacity) {
      *end = (pTsdbReadHandle->outputCapacity - numOfExisted) + startPos - 1;
    } else {
      *end = endPos;
    }

    *start = startPos;
  } else {
    int32_t remain = (startPos - endPos) + 1;
    if (remain + numOfExisted > pTsdbReadHandle->outputCapacity) {
      *end = startPos + 1 - (pTsdbReadHandle->outputCapacity - numOfExisted);
    } else {
      *end = endPos;
    }

    *start = *end;
    *end = startPos;
  }
}

static void updateInfoAfterMerge(STsdbReadHandle* pTsdbReadHandle, STableCheckInfo* pCheckInfo, int32_t numOfRows,
                                 int32_t endPos) {
  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  pCheckInfo->lastKey = cur->lastKey;
  pTsdbReadHandle->realNumOfRows = numOfRows;
  cur->rows = numOfRows;
  cur->pos = endPos;
}

static void doCheckGeneratedBlockRange(STsdbReadHandle* pTsdbReadHandle) {
  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  if (cur->rows > 0) {
    if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
      assert(cur->win.skey >= pTsdbReadHandle->window.skey && cur->win.ekey <= pTsdbReadHandle->window.ekey);
    } else {
      assert(cur->win.skey >= pTsdbReadHandle->window.ekey && cur->win.ekey <= pTsdbReadHandle->window.skey);
    }

    SColumnInfoData* pColInfoData = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, 0);
    assert(cur->win.skey == ((TSKEY*)pColInfoData->pData)[0] &&
           cur->win.ekey == ((TSKEY*)pColInfoData->pData)[cur->rows - 1]);
  } else {
    cur->win = pTsdbReadHandle->window;

    int32_t step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;
    cur->lastKey = pTsdbReadHandle->window.ekey + step;
  }
}

static void copyAllRemainRowsFromFileBlock(STsdbReadHandle* pTsdbReadHandle, STableCheckInfo* pCheckInfo,
                                           SDataBlockInfo* pBlockInfo, int32_t endPos) {
  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
  TSKEY*     tsArray = pCols->cols[0].pData;

  bool ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

  int32_t step = ascScan ? 1 : -1;

  int32_t start = cur->pos;
  int32_t end = endPos;

  if (!ascScan) {
    TSWAP(start, end);
  }

  assert(pTsdbReadHandle->outputCapacity >= (end - start + 1));
  int32_t numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, 0, start, end);

  // the time window should always be ascending order: skey <= ekey
  cur->win = (STimeWindow){.skey = tsArray[start], .ekey = tsArray[end]};
  cur->mixBlock = (numOfRows != pBlockInfo->rows);
  cur->lastKey = tsArray[endPos] + step;
  cur->blockCompleted = (ascScan ? (endPos == pBlockInfo->rows - 1) : (endPos == 0));

  // The value of pos may be -1 or pBlockInfo->rows, and it is invalid in both cases.
  int32_t pos = endPos + step;
  updateInfoAfterMerge(pTsdbReadHandle, pCheckInfo, numOfRows, pos);
  doCheckGeneratedBlockRange(pTsdbReadHandle);

  tsdbDebug("%p uid:%" PRIu64 ", data block created, mixblock:%d, brange:%" PRIu64 "-%" PRIu64 " rows:%d, %s",
            pTsdbReadHandle, pCheckInfo->tableId, cur->mixBlock, cur->win.skey, cur->win.ekey, cur->rows,
            pTsdbReadHandle->idStr);
}

int32_t getEndPosInDataBlock(STsdbReadHandle* pTsdbReadHandle, SDataBlockInfo* pBlockInfo) {
  // NOTE: reverse the order to find the end position in data block
  int32_t endPos = -1;
  bool    ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);
  int32_t order = ascScan ? TSDB_ORDER_DESC : TSDB_ORDER_ASC;

  SQueryFilePos* cur = &pTsdbReadHandle->cur;
  SDataCols*     pCols = pTsdbReadHandle->rhelper.pDCols[0];

  if (pTsdbReadHandle->outputCapacity >= pBlockInfo->rows) {
    if (ascScan && pTsdbReadHandle->window.ekey >= pBlockInfo->window.ekey) {
      endPos = pBlockInfo->rows - 1;
      cur->mixBlock = (cur->pos != 0);
    } else if ((!ascScan) && pTsdbReadHandle->window.ekey <= pBlockInfo->window.skey) {
      endPos = 0;
      cur->mixBlock = (cur->pos != pBlockInfo->rows - 1);
    } else {
      assert(pCols->numOfRows > 0);
      endPos = doBinarySearchKey(pCols->cols[0].pData, pCols->numOfRows, pTsdbReadHandle->window.ekey, order);
      cur->mixBlock = true;
    }
  } else {
    if (ascScan && pTsdbReadHandle->window.ekey >= pBlockInfo->window.ekey) {
      endPos = TMIN(cur->pos + pTsdbReadHandle->outputCapacity - 1, pBlockInfo->rows - 1);
    } else if ((!ascScan) && pTsdbReadHandle->window.ekey <= pBlockInfo->window.skey) {
      endPos = TMAX(cur->pos - pTsdbReadHandle->outputCapacity + 1, 0);
    } else {
      ASSERT(pCols->numOfRows > 0);
      endPos = doBinarySearchKey(pCols->cols[0].pData, pCols->numOfRows, pTsdbReadHandle->window.ekey, order);

      // current data is more than the capacity
      int32_t size = abs(cur->pos - endPos) + 1;
      if (size > pTsdbReadHandle->outputCapacity) {
        int32_t delta = size - pTsdbReadHandle->outputCapacity;
        if (ascScan) {
          endPos -= delta;
        } else {
          endPos += delta;
        }
      }
    }
    cur->mixBlock = true;
  }

  return endPos;
}

// only return the qualified data to client in terms of query time window, data rows in the same block but do not
// be included in the query time window will be discarded
static void doMergeTwoLevelData(STsdbReadHandle* pTsdbReadHandle, STableCheckInfo* pCheckInfo, SBlock* pBlock) {
  SQueryFilePos* cur = &pTsdbReadHandle->cur;
  SDataBlockInfo blockInfo = GET_FILE_DATA_BLOCK_INFO(pCheckInfo, pBlock);
  STsdbCfg*      pCfg = REPO_CFG(pTsdbReadHandle->pTsdb);

  initTableMemIterator(pTsdbReadHandle, pCheckInfo);

  SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
  assert(pCols->cols[0].type == TSDB_DATA_TYPE_TIMESTAMP && pCols->cols[0].colId == PRIMARYKEY_TIMESTAMP_COL_ID &&
         cur->pos >= 0 && cur->pos < pBlock->numOfRows);
  // Even Multi-Version supported, the records with duplicated TSKEY would be merged inside of tsdbLoadData interface.
  TSKEY* tsArray = pCols->cols[0].pData;
  assert(pCols->numOfRows == pBlock->numOfRows && tsArray[0] == pBlock->minKey.ts &&
         tsArray[pBlock->numOfRows - 1] == pBlock->maxKey.ts);

  bool    ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);
  int32_t step = ascScan ? 1 : -1;

  // for search the endPos, so the order needs to reverse
  int32_t order = ascScan ? TSDB_ORDER_DESC : TSDB_ORDER_ASC;

  int32_t numOfCols = (int32_t)(QH_GET_NUM_OF_COLS(pTsdbReadHandle));
  int32_t endPos = getEndPosInDataBlock(pTsdbReadHandle, &blockInfo);

  STimeWindow* pWin = &blockInfo.window;
  tsdbDebug("%p uid:%" PRIu64 " start merge data block, file block range:%" PRIu64 "-%" PRIu64
            " rows:%d, start:%d, end:%d, %s",
            pTsdbReadHandle, pCheckInfo->tableId, pWin->skey, pWin->ekey, blockInfo.rows, cur->pos, endPos,
            pTsdbReadHandle->idStr);

  // compared with the data from in-memory buffer, to generate the correct timestamp array list
  int32_t numOfRows = 0;
  int32_t curRow = 0;

  int16_t   rv1 = -1;
  int16_t   rv2 = -1;
  STSchema* pSchema1 = NULL;
  STSchema* pSchema2 = NULL;

  int32_t pos = cur->pos;
  cur->win = TSWINDOW_INITIALIZER;
  bool adjustPos = false;

  // no data in buffer, load data from file directly
  if (pCheckInfo->iiter == NULL && pCheckInfo->iter == NULL) {
    copyAllRemainRowsFromFileBlock(pTsdbReadHandle, pCheckInfo, &blockInfo, endPos);
    return;
  } else if (pCheckInfo->iter != NULL || pCheckInfo->iiter != NULL) {
    SSkipListNode* node = NULL;
    TSKEY          lastKeyAppend = TSKEY_INITIAL_VAL;

    do {
      STSRow* row2 = NULL;
      STSRow* row1 = getSRowInTableMem(pCheckInfo, pTsdbReadHandle->order, pCfg->update, &row2, TD_VER_MAX);
      if (row1 == NULL) {
        break;
      }

      TSKEY key = TD_ROW_KEY(row1);
      if ((key > pTsdbReadHandle->window.ekey && ascScan) || (key < pTsdbReadHandle->window.ekey && !ascScan)) {
        break;
      }

      if (adjustPos) {
        if (key == lastKeyAppend) {
          pos -= step;
        }
        adjustPos = false;
      }

      if (((pos > endPos || tsArray[pos] > pTsdbReadHandle->window.ekey) && ascScan) ||
          ((pos < endPos || tsArray[pos] < pTsdbReadHandle->window.ekey) && !ascScan)) {
        break;
      }

      if ((key < tsArray[pos] && ascScan) || (key > tsArray[pos] && !ascScan)) {
        if (rv1 != TD_ROW_SVER(row1)) {
          //          pSchema1 = tsdbGetTableSchemaByVersion(pTable, memRowVersion(row1));
          rv1 = TD_ROW_SVER(row1);
        }
        if (row2 && rv2 != TD_ROW_SVER(row2)) {
          //          pSchema2 = tsdbGetTableSchemaByVersion(pTable, memRowVersion(row2));
          rv2 = TD_ROW_SVER(row2);
        }

        numOfRows +=
            mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, &curRow, row1, row2, numOfCols,
                               pCheckInfo->tableId, pSchema1, pSchema2, pCfg->update, &lastKeyAppend);
        if (cur->win.skey == TSKEY_INITIAL_VAL) {
          cur->win.skey = key;
        }

        cur->win.ekey = key;
        cur->lastKey = key + step;
        cur->mixBlock = true;
        moveToNextRowInMem(pCheckInfo);
      } else if (key == tsArray[pos]) {  // data in buffer has the same timestamp of data in file block, ignore it
#if 0
        if (pCfg->update) {
          if (pCfg->update == TD_ROW_PARTIAL_UPDATE) {
            doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, numOfRows, pos, pos);
          }
          if (rv1 != TD_ROW_SVER(row1)) {
            //            pSchema1 = tsdbGetTableSchemaByVersion(pTable, memRowVersion(row1));
            rv1 = TD_ROW_SVER(row1);
          }
          if (row2 && rv2 != TD_ROW_SVER(row2)) {
            //            pSchema2 = tsdbGetTableSchemaByVersion(pTable, memRowVersion(row2));
            rv2 = TD_ROW_SVER(row2);
          }

          bool forceSetNull = pCfg->update != TD_ROW_PARTIAL_UPDATE;
          mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, numOfRows, row1, row2, numOfCols,
                             pCheckInfo->tableId, pSchema1, pSchema2, forceSetNull, &lastRowKey);
          numOfRows += 1;
          if (cur->win.skey == TSKEY_INITIAL_VAL) {
            cur->win.skey = key;
          }

          cur->win.ekey = key;
          cur->lastKey = key + step;
          cur->mixBlock = true;

          moveToNextRowInMem(pCheckInfo);
          pos += step;
        } else {
          moveToNextRowInMem(pCheckInfo);
        }
#endif
        if (TD_SUPPORT_UPDATE(pCfg->update)) {
          if (lastKeyAppend != key) {
            if (lastKeyAppend != TSKEY_INITIAL_VAL) {
              ++curRow;
            }
            lastKeyAppend = key;
          }
          // load data from file firstly
          numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, curRow, pos, pos);

          if (rv1 != TD_ROW_SVER(row1)) {
            rv1 = TD_ROW_SVER(row1);
          }
          if (row2 && rv2 != TD_ROW_SVER(row2)) {
            rv2 = TD_ROW_SVER(row2);
          }

          // still assign data into current row
          numOfRows +=
              mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, &curRow, row1, row2, numOfCols,
                                 pCheckInfo->tableId, pSchema1, pSchema2, pCfg->update, &lastKeyAppend);

          if (cur->win.skey == TSKEY_INITIAL_VAL) {
            cur->win.skey = key;
          }

          cur->win.ekey = key;
          cur->lastKey = key + step;
          cur->mixBlock = true;

          moveToNextRowInMem(pCheckInfo);

          pos += step;
          adjustPos = true;
        } else {
          // discard the memory record
          moveToNextRowInMem(pCheckInfo);
        }
      } else if ((key > tsArray[pos] && ascScan) || (key < tsArray[pos] && !ascScan)) {
        if (cur->win.skey == TSKEY_INITIAL_VAL) {
          cur->win.skey = tsArray[pos];
        }

        int32_t end = doBinarySearchKey(pCols->cols[0].pData, pCols->numOfRows, key, order);
        assert(end != -1);

        if (tsArray[end] == key) {  // the value of key in cache equals to the end timestamp value, ignore it
#if 0
          if (pCfg->update == TD_ROW_DISCARD_UPDATE) {
            moveToNextRowInMem(pCheckInfo);
          } else {
            end -= step;
          }
#endif
          if (!TD_SUPPORT_UPDATE(pCfg->update)) {
            moveToNextRowInMem(pCheckInfo);
          } else {
            end -= step;
          }
        }

        int32_t qstart = 0, qend = 0;
        getQualifiedRowsPos(pTsdbReadHandle, pos, end, numOfRows, &qstart, &qend);

        if ((lastKeyAppend != TSKEY_INITIAL_VAL) && (lastKeyAppend != (ascScan ? tsArray[qstart] : tsArray[qend]))) {
          ++curRow;
        }

        numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, curRow, qstart, qend);
        pos += (qend - qstart + 1) * step;
        if (numOfRows > 0) {
          curRow = numOfRows - 1;
        }

        cur->win.ekey = ascScan ? tsArray[qend] : tsArray[qstart];
        cur->lastKey = cur->win.ekey + step;
        lastKeyAppend = cur->win.ekey;
      }
    } while (numOfRows < pTsdbReadHandle->outputCapacity);

    if (numOfRows < pTsdbReadHandle->outputCapacity) {
      /**
       * if cache is empty, load remain file block data. In contrast, if there are remain data in cache, do NOT
       * copy them all to result buffer, since it may be overlapped with file data block.
       */
      if (node == NULL || ((TD_ROW_KEY((STSRow*)SL_GET_NODE_DATA(node)) > pTsdbReadHandle->window.ekey) && ascScan) ||
          ((TD_ROW_KEY((STSRow*)SL_GET_NODE_DATA(node)) < pTsdbReadHandle->window.ekey) && !ascScan)) {
        // no data in cache or data in cache is greater than the ekey of time window, load data from file block
        if (cur->win.skey == TSKEY_INITIAL_VAL) {
          cur->win.skey = tsArray[pos];
        }

        int32_t start = -1, end = -1;
        getQualifiedRowsPos(pTsdbReadHandle, pos, endPos, numOfRows, &start, &end);

        numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, numOfRows, start, end);
        pos += (end - start + 1) * step;

        cur->win.ekey = ascScan ? tsArray[end] : tsArray[start];
        cur->lastKey = cur->win.ekey + step;
        cur->mixBlock = true;
      }
    }
  }

  cur->blockCompleted = (((pos > endPos || cur->lastKey > pTsdbReadHandle->window.ekey) && ascScan) ||
                         ((pos < endPos || cur->lastKey < pTsdbReadHandle->window.ekey) && !ascScan));

  if (!ascScan) {
    TSWAP(cur->win.skey, cur->win.ekey);
  }

  updateInfoAfterMerge(pTsdbReadHandle, pCheckInfo, numOfRows, pos);
  doCheckGeneratedBlockRange(pTsdbReadHandle);

  tsdbDebug("%p uid:%" PRIu64 ", data block created, mixblock:%d, brange:%" PRIu64 "-%" PRIu64 " rows:%d, %s",
            pTsdbReadHandle, pCheckInfo->tableId, cur->mixBlock, cur->win.skey, cur->win.ekey, cur->rows,
            pTsdbReadHandle->idStr);
}

int32_t binarySearchForKey(char* pValue, int num, TSKEY key, int order) {
  int    firstPos, lastPos, midPos = -1;
  int    numOfRows;
  TSKEY* keyList;

  if (num <= 0) return -1;

  keyList = (TSKEY*)pValue;
  firstPos = 0;
  lastPos = num - 1;

  if (order == TSDB_ORDER_DESC) {
    // find the first position which is smaller than the key
    while (1) {
      if (key >= keyList[lastPos]) return lastPos;
      if (key == keyList[firstPos]) return firstPos;
      if (key < keyList[firstPos]) return firstPos - 1;

      numOfRows = lastPos - firstPos + 1;
      midPos = (numOfRows >> 1) + firstPos;

      if (key < keyList[midPos]) {
        lastPos = midPos - 1;
      } else if (key > keyList[midPos]) {
        firstPos = midPos + 1;
      } else {
        break;
      }
    }

  } else {
    // find the first position which is bigger than the key
    while (1) {
      if (key <= keyList[firstPos]) return firstPos;
      if (key == keyList[lastPos]) return lastPos;

      if (key > keyList[lastPos]) {
        lastPos = lastPos + 1;
        if (lastPos >= num)
          return -1;
        else
          return lastPos;
      }

      numOfRows = lastPos - firstPos + 1;
      midPos = (numOfRows >> 1) + firstPos;

      if (key < keyList[midPos]) {
        lastPos = midPos - 1;
      } else if (key > keyList[midPos]) {
        firstPos = midPos + 1;
      } else {
        break;
      }
    }
  }

  return midPos;
}

static void cleanBlockOrderSupporter(SBlockOrderSupporter* pSupporter, int32_t numOfTables) {
  taosMemoryFreeClear(pSupporter->numOfBlocksPerTable);
  taosMemoryFreeClear(pSupporter->blockIndexArray);

  for (int32_t i = 0; i < numOfTables; ++i) {
    STableBlockInfo* pBlockInfo = pSupporter->pDataBlockInfo[i];
    taosMemoryFreeClear(pBlockInfo);
  }

  taosMemoryFreeClear(pSupporter->pDataBlockInfo);
}

static int32_t dataBlockOrderCompar(const void* pLeft, const void* pRight, void* param) {
  int32_t leftTableIndex = *(int32_t*)pLeft;
  int32_t rightTableIndex = *(int32_t*)pRight;

  SBlockOrderSupporter* pSupporter = (SBlockOrderSupporter*)param;

  int32_t leftTableBlockIndex = pSupporter->blockIndexArray[leftTableIndex];
  int32_t rightTableBlockIndex = pSupporter->blockIndexArray[rightTableIndex];

  if (leftTableBlockIndex > pSupporter->numOfBlocksPerTable[leftTableIndex]) {
    /* left block is empty */
    return 1;
  } else if (rightTableBlockIndex > pSupporter->numOfBlocksPerTable[rightTableIndex]) {
    /* right block is empty */
    return -1;
  }

  STableBlockInfo* pLeftBlockInfoEx = &pSupporter->pDataBlockInfo[leftTableIndex][leftTableBlockIndex];
  STableBlockInfo* pRightBlockInfoEx = &pSupporter->pDataBlockInfo[rightTableIndex][rightTableBlockIndex];

  //    assert(pLeftBlockInfoEx->compBlock->offset != pRightBlockInfoEx->compBlock->offset);
#if 0  // TODO: temporarily comment off requested by Dr. Liao
  if (pLeftBlockInfoEx->compBlock->offset == pRightBlockInfoEx->compBlock->offset &&
      pLeftBlockInfoEx->compBlock->last == pRightBlockInfoEx->compBlock->last) {
    tsdbError("error in header file, two block with same offset:%" PRId64, (int64_t)pLeftBlockInfoEx->compBlock->offset);
  }
#endif

  return pLeftBlockInfoEx->compBlock->offset > pRightBlockInfoEx->compBlock->offset ? 1 : -1;
}

static int32_t createDataBlocksInfo(STsdbReadHandle* pTsdbReadHandle, int32_t numOfBlocks, int32_t* numOfAllocBlocks) {
  size_t size = sizeof(STableBlockInfo) * numOfBlocks;

  if (pTsdbReadHandle->allocSize < size) {
    pTsdbReadHandle->allocSize = (int32_t)size;
    char* tmp = taosMemoryRealloc(pTsdbReadHandle->pDataBlockInfo, pTsdbReadHandle->allocSize);
    if (tmp == NULL) {
      return TSDB_CODE_TDB_OUT_OF_MEMORY;
    }

    pTsdbReadHandle->pDataBlockInfo = (STableBlockInfo*)tmp;
  }

  memset(pTsdbReadHandle->pDataBlockInfo, 0, size);
  *numOfAllocBlocks = numOfBlocks;

  // access data blocks according to the offset of each block in asc/desc order.
  int32_t numOfTables = (int32_t)taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

  SBlockOrderSupporter sup = {0};
  sup.numOfTables = numOfTables;
  sup.numOfBlocksPerTable = taosMemoryCalloc(1, sizeof(int32_t) * numOfTables);
  sup.blockIndexArray = taosMemoryCalloc(1, sizeof(int32_t) * numOfTables);
  sup.pDataBlockInfo = taosMemoryCalloc(1, POINTER_BYTES * numOfTables);

  if (sup.numOfBlocksPerTable == NULL || sup.blockIndexArray == NULL || sup.pDataBlockInfo == NULL) {
    cleanBlockOrderSupporter(&sup, 0);
    return TSDB_CODE_TDB_OUT_OF_MEMORY;
  }

  int32_t cnt = 0;
  int32_t numOfQualTables = 0;

  for (int32_t j = 0; j < numOfTables; ++j) {
    STableCheckInfo* pTableCheck = (STableCheckInfo*)taosArrayGet(pTsdbReadHandle->pTableCheckInfo, j);
    if (pTableCheck->numOfBlocks <= 0) {
      continue;
    }

    SBlock* pBlock = pTableCheck->pCompInfo->blocks;
    sup.numOfBlocksPerTable[numOfQualTables] = pTableCheck->numOfBlocks;

    char* buf = taosMemoryMalloc(sizeof(STableBlockInfo) * pTableCheck->numOfBlocks);
    if (buf == NULL) {
      cleanBlockOrderSupporter(&sup, numOfQualTables);
      return TSDB_CODE_TDB_OUT_OF_MEMORY;
    }

    sup.pDataBlockInfo[numOfQualTables] = (STableBlockInfo*)buf;

    for (int32_t k = 0; k < pTableCheck->numOfBlocks; ++k) {
      STableBlockInfo* pBlockInfo = &sup.pDataBlockInfo[numOfQualTables][k];

      pBlockInfo->compBlock = &pBlock[k];
      pBlockInfo->pTableCheckInfo = pTableCheck;
      cnt++;
    }

    numOfQualTables++;
  }

  assert(numOfBlocks == cnt);

  // since there is only one table qualified, blocks are not sorted
  if (numOfQualTables == 1) {
    memcpy(pTsdbReadHandle->pDataBlockInfo, sup.pDataBlockInfo[0], sizeof(STableBlockInfo) * numOfBlocks);
    cleanBlockOrderSupporter(&sup, numOfQualTables);

    tsdbDebug("%p create data blocks info struct completed for 1 table, %d blocks not sorted %s", pTsdbReadHandle, cnt,
              pTsdbReadHandle->idStr);
    return TSDB_CODE_SUCCESS;
  }

  tsdbDebug("%p create data blocks info struct completed, %d blocks in %d tables %s", pTsdbReadHandle, cnt,
            numOfQualTables, pTsdbReadHandle->idStr);

  assert(cnt <= numOfBlocks && numOfQualTables <= numOfTables);  // the pTableQueryInfo[j]->numOfBlocks may be 0
  sup.numOfTables = numOfQualTables;

  SMultiwayMergeTreeInfo* pTree = NULL;
  uint8_t                 ret = tMergeTreeCreate(&pTree, sup.numOfTables, &sup, dataBlockOrderCompar);
  if (ret != TSDB_CODE_SUCCESS) {
    cleanBlockOrderSupporter(&sup, numOfTables);
    return TSDB_CODE_TDB_OUT_OF_MEMORY;
  }

  int32_t numOfTotal = 0;

  while (numOfTotal < cnt) {
    int32_t pos = tMergeTreeGetChosenIndex(pTree);
    int32_t index = sup.blockIndexArray[pos]++;

    STableBlockInfo* pBlocksInfo = sup.pDataBlockInfo[pos];
    pTsdbReadHandle->pDataBlockInfo[numOfTotal++] = pBlocksInfo[index];

    // set data block index overflow, in order to disable the offset comparator
    if (sup.blockIndexArray[pos] >= sup.numOfBlocksPerTable[pos]) {
      sup.blockIndexArray[pos] = sup.numOfBlocksPerTable[pos] + 1;
    }

    tMergeTreeAdjust(pTree, tMergeTreeGetAdjustIndex(pTree));
  }

  /*
   * available when no import exists
   * for(int32_t i = 0; i < cnt - 1; ++i) {
   *   assert((*pDataBlockInfo)[i].compBlock->offset < (*pDataBlockInfo)[i+1].compBlock->offset);
   * }
   */

  tsdbDebug("%p %d data blocks sort completed, %s", pTsdbReadHandle, cnt, pTsdbReadHandle->idStr);
  cleanBlockOrderSupporter(&sup, numOfTables);
  taosMemoryFree(pTree);

  return TSDB_CODE_SUCCESS;
}

static int32_t getFirstFileDataBlock(STsdbReadHandle* pTsdbReadHandle, bool* exists);

static int32_t getDataBlock(STsdbReadHandle* pTsdbReadHandle, STableBlockInfo* pNext, bool* exists) {
  int32_t        step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;
  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  while (1) {
    int32_t code = loadFileDataBlock(pTsdbReadHandle, pNext->compBlock, pNext->pTableCheckInfo, exists);
    if (code != TSDB_CODE_SUCCESS || *exists) {
      return code;
    }

    if ((cur->slot == pTsdbReadHandle->numOfBlocks - 1 && ASCENDING_TRAVERSE(pTsdbReadHandle->order)) ||
        (cur->slot == 0 && !ASCENDING_TRAVERSE(pTsdbReadHandle->order))) {
      // all data blocks in current file has been checked already, try next file if exists
      return getFirstFileDataBlock(pTsdbReadHandle, exists);
    } else {  // next block of the same file
      cur->slot += step;
      cur->mixBlock = false;
      cur->blockCompleted = false;
      pNext = &pTsdbReadHandle->pDataBlockInfo[cur->slot];
    }
  }
}

static int32_t getFirstFileDataBlock(STsdbReadHandle* pTsdbReadHandle, bool* exists) {
  pTsdbReadHandle->numOfBlocks = 0;
  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  int32_t code = TSDB_CODE_SUCCESS;

  int32_t numOfBlocks = 0;
  int32_t numOfTables = (int32_t)taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

  STsdbKeepCfg* pCfg = REPO_KEEP_CFG(pTsdbReadHandle->pTsdb);
  STimeWindow   win = TSWINDOW_INITIALIZER;

  while (true) {
    tsdbRLockFS(REPO_FS(pTsdbReadHandle->pTsdb));

    if ((pTsdbReadHandle->pFileGroup = tsdbFSIterNext(&pTsdbReadHandle->fileIter)) == NULL) {
      tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
      break;
    }

    tsdbGetFidKeyRange(pCfg->days, pCfg->precision, pTsdbReadHandle->pFileGroup->fid, &win.skey, &win.ekey);

    // current file are not overlapped with query time window, ignore remain files
    if ((ASCENDING_TRAVERSE(pTsdbReadHandle->order) && win.skey > pTsdbReadHandle->window.ekey) ||
        (!ASCENDING_TRAVERSE(pTsdbReadHandle->order) && win.ekey < pTsdbReadHandle->window.ekey)) {
      tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
      tsdbDebug("%p remain files are not qualified for qrange:%" PRId64 "-%" PRId64 ", ignore, %s", pTsdbReadHandle,
                pTsdbReadHandle->window.skey, pTsdbReadHandle->window.ekey, pTsdbReadHandle->idStr);
      pTsdbReadHandle->pFileGroup = NULL;
      assert(pTsdbReadHandle->numOfBlocks == 0);
      break;
    }

    if (tsdbSetAndOpenReadFSet(&pTsdbReadHandle->rhelper, pTsdbReadHandle->pFileGroup) < 0) {
      tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
      code = terrno;
      break;
    }

    tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));

    if (tsdbLoadBlockIdx(&pTsdbReadHandle->rhelper) < 0) {
      code = terrno;
      break;
    }

    if ((code = getFileCompInfo(pTsdbReadHandle, &numOfBlocks)) != TSDB_CODE_SUCCESS) {
      break;
    }

    tsdbDebug("%p %d blocks found in file for %d table(s), fid:%d, %s", pTsdbReadHandle, numOfBlocks, numOfTables,
              pTsdbReadHandle->pFileGroup->fid, pTsdbReadHandle->idStr);

    assert(numOfBlocks >= 0);
    if (numOfBlocks == 0) {
      continue;
    }

    // todo return error code to query engine
    if ((code = createDataBlocksInfo(pTsdbReadHandle, numOfBlocks, &pTsdbReadHandle->numOfBlocks)) !=
        TSDB_CODE_SUCCESS) {
      break;
    }

    assert(numOfBlocks >= pTsdbReadHandle->numOfBlocks);
    if (pTsdbReadHandle->numOfBlocks > 0) {
      break;
    }
  }

  // no data in file anymore
  if (pTsdbReadHandle->numOfBlocks <= 0 || code != TSDB_CODE_SUCCESS) {
    if (code == TSDB_CODE_SUCCESS) {
      assert(pTsdbReadHandle->pFileGroup == NULL);
    }

    cur->fid = INT32_MIN;  // denote that there are no data in file anymore
    *exists = false;
    return code;
  }

  assert(pTsdbReadHandle->pFileGroup != NULL && pTsdbReadHandle->numOfBlocks > 0);
  cur->slot = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 0 : pTsdbReadHandle->numOfBlocks - 1;
  cur->fid = pTsdbReadHandle->pFileGroup->fid;

  STableBlockInfo* pBlockInfo = &pTsdbReadHandle->pDataBlockInfo[cur->slot];
  return getDataBlock(pTsdbReadHandle, pBlockInfo, exists);
}

static bool isEndFileDataBlock(SQueryFilePos* cur, int32_t numOfBlocks, bool ascTrav) {
  assert(cur != NULL && numOfBlocks > 0);
  return (cur->slot == numOfBlocks - 1 && ascTrav) || (cur->slot == 0 && !ascTrav);
}

static void moveToNextDataBlockInCurrentFile(STsdbReadHandle* pTsdbReadHandle) {
  int32_t step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;

  SQueryFilePos* cur = &pTsdbReadHandle->cur;
  assert(cur->slot < pTsdbReadHandle->numOfBlocks && cur->slot >= 0);

  cur->slot += step;
  cur->mixBlock = false;
  cur->blockCompleted = false;
}

static int32_t getBucketIndex(int32_t startRow, int32_t bucketRange, int32_t numOfRows) {
  return (numOfRows - startRow) / bucketRange;
}

int32_t tsdbGetFileBlocksDistInfo(tsdbReaderT* queryHandle, STableBlockDistInfo* pTableBlockInfo) {
  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)queryHandle;

  pTableBlockInfo->totalSize = 0;
  pTableBlockInfo->totalRows = 0;

  STsdbFS* pFileHandle = REPO_FS(pTsdbReadHandle->pTsdb);

  // find the start data block in file
  pTsdbReadHandle->locateStart = true;
  STsdbKeepCfg* pCfg = REPO_KEEP_CFG(pTsdbReadHandle->pTsdb);
  int32_t       fid = getFileIdFromKey(pTsdbReadHandle->window.skey, pCfg->days, pCfg->precision);

  tsdbRLockFS(pFileHandle);
  tsdbFSIterInit(&pTsdbReadHandle->fileIter, pFileHandle, pTsdbReadHandle->order);
  tsdbFSIterSeek(&pTsdbReadHandle->fileIter, fid);
  tsdbUnLockFS(pFileHandle);

  STsdbCfg* pc = REPO_CFG(pTsdbReadHandle->pTsdb);
  pTableBlockInfo->defMinRows = pc->minRows;
  pTableBlockInfo->defMaxRows = pc->maxRows;

  int32_t bucketRange = ceil((pc->maxRows - pc->minRows) / 20.0);

  pTableBlockInfo->numOfFiles += 1;

  int32_t     code = TSDB_CODE_SUCCESS;
  int32_t     numOfBlocks = 0;
  int32_t     numOfTables = (int32_t)taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
  int         defaultRows = 4096;
  STimeWindow win = TSWINDOW_INITIALIZER;

  while (true) {
    numOfBlocks = 0;
    tsdbRLockFS(REPO_FS(pTsdbReadHandle->pTsdb));

    if ((pTsdbReadHandle->pFileGroup = tsdbFSIterNext(&pTsdbReadHandle->fileIter)) == NULL) {
      tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
      break;
    }

    tsdbGetFidKeyRange(pCfg->days, pCfg->precision, pTsdbReadHandle->pFileGroup->fid, &win.skey, &win.ekey);

    // current file are not overlapped with query time window, ignore remain files
    if ((win.skey > pTsdbReadHandle->window.ekey) /* || (!ascTraverse && win.ekey < pTsdbReadHandle->window.ekey)*/) {
      tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
      tsdbDebug("%p remain files are not qualified for qrange:%" PRId64 "-%" PRId64 ", ignore, %s", pTsdbReadHandle,
                pTsdbReadHandle->window.skey, pTsdbReadHandle->window.ekey, pTsdbReadHandle->idStr);
      pTsdbReadHandle->pFileGroup = NULL;
      break;
    }

    pTableBlockInfo->numOfFiles += 1;
    if (tsdbSetAndOpenReadFSet(&pTsdbReadHandle->rhelper, pTsdbReadHandle->pFileGroup) < 0) {
      tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
      code = terrno;
      break;
    }

    tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));

    if (tsdbLoadBlockIdx(&pTsdbReadHandle->rhelper) < 0) {
      code = terrno;
      break;
    }

    if ((code = getFileCompInfo(pTsdbReadHandle, &numOfBlocks)) != TSDB_CODE_SUCCESS) {
      break;
    }

    tsdbDebug("%p %d blocks found in file for %d table(s), fid:%d, %s", pTsdbReadHandle, numOfBlocks, numOfTables,
              pTsdbReadHandle->pFileGroup->fid, pTsdbReadHandle->idStr);

    if (numOfBlocks == 0) {
      continue;
    }

    pTableBlockInfo->numOfBlocks += numOfBlocks;

    for (int32_t i = 0; i < numOfTables; ++i) {
      STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);

      SBlock* pBlock = pCheckInfo->pCompInfo->blocks;

      for (int32_t j = 0; j < pCheckInfo->numOfBlocks; ++j) {
        pTableBlockInfo->totalSize += pBlock[j].len;

        int32_t numOfRows = pBlock[j].numOfRows;
        pTableBlockInfo->totalRows += numOfRows;

        if (numOfRows > pTableBlockInfo->maxRows) {
          pTableBlockInfo->maxRows = numOfRows;
        }

        if (numOfRows < pTableBlockInfo->minRows) {
          pTableBlockInfo->minRows = numOfRows;
        }

        if (numOfRows < defaultRows) {
          pTableBlockInfo->numOfSmallBlocks += 1;
        }

        int32_t bucketIndex = getBucketIndex(pTableBlockInfo->defMinRows, bucketRange, numOfRows);
        pTableBlockInfo->blockRowsHisto[bucketIndex]++;
      }
    }
  }

  pTableBlockInfo->numOfTables = numOfTables;
  return code;
}

static int32_t getDataBlocksInFiles(STsdbReadHandle* pTsdbReadHandle, bool* exists) {
  STsdbFS*       pFileHandle = REPO_FS(pTsdbReadHandle->pTsdb);
  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  // find the start data block in file
  if (!pTsdbReadHandle->locateStart) {
    pTsdbReadHandle->locateStart = true;
    STsdbKeepCfg* pCfg = REPO_KEEP_CFG(pTsdbReadHandle->pTsdb);
    int32_t       fid = getFileIdFromKey(pTsdbReadHandle->window.skey, pCfg->days, pCfg->precision);

    tsdbRLockFS(pFileHandle);
    tsdbFSIterInit(&pTsdbReadHandle->fileIter, pFileHandle, pTsdbReadHandle->order);
    tsdbFSIterSeek(&pTsdbReadHandle->fileIter, fid);
    tsdbUnLockFS(pFileHandle);

    return getFirstFileDataBlock(pTsdbReadHandle, exists);
  } else {
    // check if current file block is all consumed
    STableBlockInfo* pBlockInfo = &pTsdbReadHandle->pDataBlockInfo[cur->slot];
    STableCheckInfo* pCheckInfo = pBlockInfo->pTableCheckInfo;

    // current block is done, try next
    if ((!cur->mixBlock) || cur->blockCompleted) {
      // all data blocks in current file has been checked already, try next file if exists
    } else {
      tsdbDebug("%p continue in current data block, index:%d, pos:%d, %s", pTsdbReadHandle, cur->slot, cur->pos,
                pTsdbReadHandle->idStr);
      int32_t code = handleDataMergeIfNeeded(pTsdbReadHandle, pBlockInfo->compBlock, pCheckInfo);
      *exists = (pTsdbReadHandle->realNumOfRows > 0);

      if (code != TSDB_CODE_SUCCESS || *exists) {
        return code;
      }
    }

    // current block is empty, try next block in file
    // all data blocks in current file has been checked already, try next file if exists
    if (isEndFileDataBlock(cur, pTsdbReadHandle->numOfBlocks, ASCENDING_TRAVERSE(pTsdbReadHandle->order))) {
      return getFirstFileDataBlock(pTsdbReadHandle, exists);
    } else {
      moveToNextDataBlockInCurrentFile(pTsdbReadHandle);
      STableBlockInfo* pNext = &pTsdbReadHandle->pDataBlockInfo[cur->slot];
      return getDataBlock(pTsdbReadHandle, pNext, exists);
    }
  }
}

static bool doHasDataInBuffer(STsdbReadHandle* pTsdbReadHandle) {
  size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

  while (pTsdbReadHandle->activeIndex < numOfTables) {
    if (hasMoreDataInCache(pTsdbReadHandle)) {
      return true;
    }

    pTsdbReadHandle->activeIndex += 1;
  }

  return false;
}

// todo not unref yet, since it is not support multi-group interpolation query
static UNUSED_FUNC void changeQueryHandleForInterpQuery(tsdbReaderT pHandle) {
  // filter the queried time stamp in the first place
  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)pHandle;

  // starts from the buffer in case of descending timestamp order check data blocks
  size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

  int32_t i = 0;
  while (i < numOfTables) {
    STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);

    // the first qualified table for interpolation query
    //    if ((pTsdbReadHandle->window.skey <= pCheckInfo->pTableObj->lastKey) &&
    //        (pCheckInfo->pTableObj->lastKey != TSKEY_INITIAL_VAL)) {
    //      break;
    //    }

    i++;
  }

  // there are no data in all the tables
  if (i == numOfTables) {
    return;
  }

  STableCheckInfo info = *(STableCheckInfo*)taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);
  taosArrayClear(pTsdbReadHandle->pTableCheckInfo);

  info.lastKey = pTsdbReadHandle->window.skey;
  taosArrayPush(pTsdbReadHandle->pTableCheckInfo, &info);
}

static int tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int maxRowsToRead, STimeWindow* win,
                                 STsdbReadHandle* pTsdbReadHandle) {
  int       numOfRows = 0;
  int       curRows = 0;
  int32_t   numOfCols = (int32_t)taosArrayGetSize(pTsdbReadHandle->pResBlock->pDataBlock);
  STsdbCfg* pCfg = REPO_CFG(pTsdbReadHandle->pTsdb);
  win->skey = TSKEY_INITIAL_VAL;

  int64_t   st = taosGetTimestampUs();
  int16_t   rv = -1;
  STSchema* pSchema = NULL;
  TSKEY     lastRowKey = TSKEY_INITIAL_VAL;

  do {
    STSRow* row = getSRowInTableMem(pCheckInfo, pTsdbReadHandle->order, pCfg->update, NULL, TD_VER_MAX);
    if (row == NULL) {
      break;
    }

    TSKEY key = TD_ROW_KEY(row);
    if ((key > maxKey && ASCENDING_TRAVERSE(pTsdbReadHandle->order)) ||
        (key < maxKey && !ASCENDING_TRAVERSE(pTsdbReadHandle->order))) {
      tsdbDebug("%p key:%" PRIu64 " beyond qrange:%" PRId64 " - %" PRId64 ", no more data in buffer", pTsdbReadHandle,
                key, pTsdbReadHandle->window.skey, pTsdbReadHandle->window.ekey);

      break;
    }

    if (win->skey == INT64_MIN) {
      win->skey = key;
    }

    win->ekey = key;
    if (rv != TD_ROW_SVER(row)) {
      pSchema = metaGetTbTSchema(REPO_META(pTsdbReadHandle->pTsdb), pCheckInfo->tableId, TD_ROW_SVER(row));
      rv = TD_ROW_SVER(row);
    }
    numOfRows += mergeTwoRowFromMem(pTsdbReadHandle, maxRowsToRead, &curRows, row, NULL, numOfCols, pCheckInfo->tableId,
                                    pSchema, NULL, pCfg->update, &lastRowKey);

    if (numOfRows >= maxRowsToRead) {
      moveToNextRowInMem(pCheckInfo);
      break;
    }

  } while (moveToNextRowInMem(pCheckInfo));

  taosMemoryFreeClear(pSchema);  // free the STSChema
  assert(numOfRows <= maxRowsToRead);

  int64_t elapsedTime = taosGetTimestampUs() - st;
  tsdbDebug("%p build data block from cache completed, elapsed time:%" PRId64 " us, numOfRows:%d, numOfCols:%d, %s",
            pTsdbReadHandle, elapsedTime, numOfRows, numOfCols, pTsdbReadHandle->idStr);

  return numOfRows;
}

void* tsdbGetIdx(SMeta* pMeta) {
  if (pMeta == NULL) {
    return NULL;
  }
  return metaGetIdx(pMeta);
}
void* tsdbGetIvtIdx(SMeta* pMeta) {
  if (pMeta == NULL) {
    return NULL;
  }
  return metaGetIvtIdx(pMeta);
}
int32_t tsdbGetAllTableList(SMeta* pMeta, uint64_t uid, SArray* list) {
  SMCtbCursor* pCur = metaOpenCtbCursor(pMeta, uid);

  while (1) {
    tb_uid_t id = metaCtbCursorNext(pCur);
    if (id == 0) {
      break;
    }

    STableKeyInfo info = {.lastKey = TSKEY_INITIAL_VAL, uid = id, .groupId = 0};
    taosArrayPush(list, &info);
  }

  metaCloseCtbCursor(pCur);
  return TSDB_CODE_SUCCESS;
}

int32_t tsdbGetCtbIdList(SMeta* pMeta, int64_t suid, SArray* list) {
  SMCtbCursor* pCur = metaOpenCtbCursor(pMeta, suid);

  while (1) {
    tb_uid_t id = metaCtbCursorNext(pCur);
    if (id == 0) {
      break;
    }

    taosArrayPush(list, &id);
  }

  metaCloseCtbCursor(pCur);
  return TSDB_CODE_SUCCESS;
}

/**
 * @brief Get all suids since suid
 *
 * @param pMeta
 * @param suid return all suids in one vnode if suid is 0
 * @param list
 * @return int32_t
 */
int32_t tsdbGetStbIdList(SMeta* pMeta, int64_t suid, SArray* list) {
  SMStbCursor* pCur = metaOpenStbCursor(pMeta, suid);
  if (!pCur) {
    return TSDB_CODE_FAILED;
  }

  while (1) {
    tb_uid_t id = metaStbCursorNext(pCur);
    if (id == 0) {
      break;
    }

    taosArrayPush(list, &id);
  }

  metaCloseStbCursor(pCur);
  return TSDB_CODE_SUCCESS;
}

static void destroyHelper(void* param) {
  if (param == NULL) {
    return;
  }

  //  tQueryInfo* pInfo = (tQueryInfo*)param;
  //  if (pInfo->optr != TSDB_RELATION_IN) {
  //    taosMemoryFreeClear(pInfo->q);
  //  } else {
  //    taosHashCleanup((SHashObj *)(pInfo->q));
  //  }

  taosMemoryFree(param);
}

#define TSDB_PREV_ROW 0x1
#define TSDB_NEXT_ROW 0x2

static bool loadBlockOfActiveTable(STsdbReadHandle* pTsdbReadHandle) {
  if (pTsdbReadHandle->checkFiles) {
    // check if the query range overlaps with the file data block
    bool exists = true;

    int32_t code = getDataBlocksInFiles(pTsdbReadHandle, &exists);
    if (code != TSDB_CODE_SUCCESS) {
      pTsdbReadHandle->checkFiles = false;
      return false;
    }

    if (exists) {
      tsdbRetrieveDataBlock((tsdbReaderT*)pTsdbReadHandle, NULL);
      if (pTsdbReadHandle->currentLoadExternalRows && pTsdbReadHandle->window.skey == pTsdbReadHandle->window.ekey) {
        SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, 0);
        assert(*(int64_t*)pColInfo->pData == pTsdbReadHandle->window.skey);
      }

      pTsdbReadHandle->currentLoadExternalRows = false;  // clear the flag, since the exact matched row is found.
      return exists;
    }

    pTsdbReadHandle->checkFiles = false;
  }

  if (hasMoreDataInCache(pTsdbReadHandle)) {
    pTsdbReadHandle->currentLoadExternalRows = false;
    return true;
  }

  // current result is empty
  if (pTsdbReadHandle->currentLoadExternalRows && pTsdbReadHandle->window.skey == pTsdbReadHandle->window.ekey &&
      pTsdbReadHandle->cur.rows == 0) {
    //    SMemTable* pMemRef = pTsdbReadHandle->pMemTable;

    //    doGetExternalRow(pTsdbReadHandle, TSDB_PREV_ROW, pMemRef);
    //    doGetExternalRow(pTsdbReadHandle, TSDB_NEXT_ROW, pMemRef);

    bool result = tsdbGetExternalRow(pTsdbReadHandle);

    //    pTsdbReadHandle->prev = doFreeColumnInfoData(pTsdbReadHandle->prev);
    //    pTsdbReadHandle->next = doFreeColumnInfoData(pTsdbReadHandle->next);
    pTsdbReadHandle->currentLoadExternalRows = false;

    return result;
  }

  return false;
}

static bool loadCachedLastRow(STsdbReadHandle* pTsdbReadHandle) {
  // the last row is cached in buffer, return it directly.
  // here note that the pTsdbReadHandle->window must be the TS_INITIALIZER
  int32_t numOfCols = (int32_t)(QH_GET_NUM_OF_COLS(pTsdbReadHandle));
  size_t  numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
  assert(numOfTables > 0 && numOfCols > 0);

  SQueryFilePos* cur = &pTsdbReadHandle->cur;

  STSRow* pRow = NULL;
  TSKEY   key = TSKEY_INITIAL_VAL;
  int32_t step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;
  TSKEY   lastRowKey = TSKEY_INITIAL_VAL;
  int32_t curRow = 0;

  if (++pTsdbReadHandle->activeIndex < numOfTables) {
    STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, pTsdbReadHandle->activeIndex);
    //    int32_t ret = tsdbGetCachedLastRow(pCheckInfo->pTableObj, &pRow, &key);
    //    if (ret != TSDB_CODE_SUCCESS) {
    //      return false;
    //    }
    mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, &curRow, pRow, NULL, numOfCols,
                       pCheckInfo->tableId, NULL, NULL, true, &lastRowKey);
    taosMemoryFreeClear(pRow);

    // update the last key value
    pCheckInfo->lastKey = key + step;

    cur->rows = 1;  // only one row
    cur->lastKey = key + step;
    cur->mixBlock = true;
    cur->win.skey = key;
    cur->win.ekey = key;

    return true;
  }

  return false;
}

// static bool loadCachedLast(STsdbReadHandle* pTsdbReadHandle) {
//  // the last row is cached in buffer, return it directly.
//  // here note that the pTsdbReadHandle->window must be the TS_INITIALIZER
//  int32_t tgNumOfCols = (int32_t)QH_GET_NUM_OF_COLS(pTsdbReadHandle);
//  size_t  numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
//  int32_t numOfRows = 0;
//  assert(numOfTables > 0 && tgNumOfCols > 0);
//  SQueryFilePos* cur = &pTsdbReadHandle->cur;
//  TSKEY priKey = TSKEY_INITIAL_VAL;
//  int32_t priIdx = -1;
//  SColumnInfoData* pColInfo = NULL;
//
//  while (++pTsdbReadHandle->activeIndex < numOfTables) {
//    STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, pTsdbReadHandle->activeIndex);
//    STable* pTable = pCheckInfo->pTableObj;
//    char* pData = NULL;
//
//    int32_t numOfCols = pTable->maxColNum;
//
//    if (pTable->lastCols == NULL || pTable->maxColNum <= 0) {
//      tsdbWarn("no last cached for table %s, uid:%" PRIu64 ",tid:%d", pTable->name->data, pTable->uid,
//      pTable->tableId); continue;
//    }
//
//    int32_t i = 0, j = 0;
//    while(i < tgNumOfCols && j < numOfCols) {
//      pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
//      if (pTable->lastCols[j].colId < pColInfo->info.colId) {
//        j++;
//        continue;
//      } else if (pTable->lastCols[j].colId > pColInfo->info.colId) {
//        i++;
//        continue;
//      }
//
//      pData = (char*)pColInfo->pData + numOfRows * pColInfo->info.bytes;
//
//      if (pTable->lastCols[j].bytes > 0) {
//        void* value = pTable->lastCols[j].pData;
//        switch (pColInfo->info.type) {
//          case TSDB_DATA_TYPE_BINARY:
//          case TSDB_DATA_TYPE_NCHAR:
//            memcpy(pData, value, varDataTLen(value));
//            break;
//          case TSDB_DATA_TYPE_NULL:
//          case TSDB_DATA_TYPE_BOOL:
//          case TSDB_DATA_TYPE_TINYINT:
//          case TSDB_DATA_TYPE_UTINYINT:
//            *(uint8_t *)pData = *(uint8_t *)value;
//            break;
//          case TSDB_DATA_TYPE_SMALLINT:
//          case TSDB_DATA_TYPE_USMALLINT:
//            *(uint16_t *)pData = *(uint16_t *)value;
//            break;
//          case TSDB_DATA_TYPE_INT:
//          case TSDB_DATA_TYPE_UINT:
//            *(uint32_t *)pData = *(uint32_t *)value;
//            break;
//          case TSDB_DATA_TYPE_BIGINT:
//          case TSDB_DATA_TYPE_UBIGINT:
//            *(uint64_t *)pData = *(uint64_t *)value;
//            break;
//          case TSDB_DATA_TYPE_FLOAT:
//            SET_FLOAT_PTR(pData, value);
//            break;
//          case TSDB_DATA_TYPE_DOUBLE:
//            SET_DOUBLE_PTR(pData, value);
//            break;
//          case TSDB_DATA_TYPE_TIMESTAMP:
//            if (pColInfo->info.colId == PRIMARYKEY_TIMESTAMP_COL_ID) {
//              priKey = tdGetKey(*(TKEY *)value);
//              priIdx = i;
//
//              i++;
//              j++;
//              continue;
//            } else {
//              *(TSKEY *)pData = *(TSKEY *)value;
//            }
//            break;
//          default:
//            memcpy(pData, value, pColInfo->info.bytes);
//        }
//
//        for (int32_t n = 0; n < tgNumOfCols; ++n) {
//          if (n == i) {
//            continue;
//          }
//
//          pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, n);
//          pData = (char*)pColInfo->pData + numOfRows * pColInfo->info.bytes;;
//
//          if (pColInfo->info.colId == PRIMARYKEY_TIMESTAMP_COL_ID) {
////            *(TSKEY *)pData = pTable->lastCols[j].ts;
//            continue;
//          }
//
//          if (pColInfo->info.type == TSDB_DATA_TYPE_BINARY || pColInfo->info.type == TSDB_DATA_TYPE_NCHAR) {
//            setVardataNull(pData, pColInfo->info.type);
//          } else {
//            setNull(pData, pColInfo->info.type, pColInfo->info.bytes);
//          }
//        }
//
//        numOfRows++;
//        assert(numOfRows < pTsdbReadHandle->outputCapacity);
//      }
//
//      i++;
//      j++;
//    }
//
//    // leave the real ts column as the last row, because last function only (not stable) use the last row as res
//    if (priKey != TSKEY_INITIAL_VAL) {
//      pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, priIdx);
//      pData = (char*)pColInfo->pData + numOfRows * pColInfo->info.bytes;
//
//      *(TSKEY *)pData = priKey;
//
//      for (int32_t n = 0; n < tgNumOfCols; ++n) {
//        if (n == priIdx) {
//          continue;
//        }
//
//        pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, n);
//        pData = (char*)pColInfo->pData + numOfRows * pColInfo->info.bytes;;
//
//        assert (pColInfo->info.colId != PRIMARYKEY_TIMESTAMP_COL_ID);
//
//        if (pColInfo->info.type == TSDB_DATA_TYPE_BINARY || pColInfo->info.type == TSDB_DATA_TYPE_NCHAR) {
//          setVardataNull(pData, pColInfo->info.type);
//        } else {
//          setNull(pData, pColInfo->info.type, pColInfo->info.bytes);
//        }
//      }
//
//      numOfRows++;
//    }
//
//    if (numOfRows > 0) {
//      cur->rows     = numOfRows;
//      cur->mixBlock = true;
//
//      return true;
//    }
//  }
//
//  return false;
//}

static bool loadDataBlockFromTableSeq(STsdbReadHandle* pTsdbReadHandle) {
  size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
  assert(numOfTables > 0);

  int64_t stime = taosGetTimestampUs();

  while (pTsdbReadHandle->activeIndex < numOfTables) {
    if (loadBlockOfActiveTable(pTsdbReadHandle)) {
      return true;
    }

    STableCheckInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, pTsdbReadHandle->activeIndex);
    pCheckInfo->numOfBlocks = 0;

    pTsdbReadHandle->activeIndex += 1;
    pTsdbReadHandle->locateStart = false;
    pTsdbReadHandle->checkFiles = true;
    pTsdbReadHandle->cur.rows = 0;
    pTsdbReadHandle->currentLoadExternalRows = pTsdbReadHandle->loadExternalRow;

    terrno = TSDB_CODE_SUCCESS;

    int64_t elapsedTime = taosGetTimestampUs() - stime;
    pTsdbReadHandle->cost.checkForNextTime += elapsedTime;
  }

  return false;
}

// handle data in cache situation
// bool tsdbNextDataBlock(tsdbReaderT pHandle, uint64_t uid)
bool tsdbNextDataBlock(tsdbReaderT pHandle) {
  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)pHandle;

  size_t numOfCols = taosArrayGetSize(pTsdbReadHandle->pResBlock->pDataBlock);
  for (int32_t i = 0; i < numOfCols; ++i) {
    SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
    colInfoDataCleanup(pColInfo, pTsdbReadHandle->outputCapacity);
  }

  if (emptyQueryTimewindow(pTsdbReadHandle)) {
    tsdbDebug("%p query window not overlaps with the data set, no result returned, %s", pTsdbReadHandle,
              pTsdbReadHandle->idStr);
    return false;
  }

  int64_t stime = taosGetTimestampUs();
  int64_t elapsedTime = stime;

  // TODO refactor: remove "type"
  if (pTsdbReadHandle->type == TSDB_QUERY_TYPE_LAST) {
    if (pTsdbReadHandle->cachelastrow == TSDB_CACHED_TYPE_LASTROW) {
      //      return loadCachedLastRow(pTsdbReadHandle);
    } else if (pTsdbReadHandle->cachelastrow == TSDB_CACHED_TYPE_LAST) {
      //      return loadCachedLast(pTsdbReadHandle);
    }
  }

  if (pTsdbReadHandle->loadType == BLOCK_LOAD_TABLE_SEQ_ORDER) {
    return loadDataBlockFromTableSeq(pTsdbReadHandle);
  } else {  // loadType == RR and Offset Order
    if (pTsdbReadHandle->checkFiles) {
      // check if the query range overlaps with the file data block
      bool exists = true;

      int32_t code = getDataBlocksInFiles(pTsdbReadHandle, &exists);
      if (code != TSDB_CODE_SUCCESS) {
        pTsdbReadHandle->activeIndex = 0;
        pTsdbReadHandle->checkFiles = false;

        return false;
      }

      if (exists) {
        pTsdbReadHandle->cost.checkForNextTime += (taosGetTimestampUs() - stime);
        return exists;
      }

      pTsdbReadHandle->activeIndex = 0;
      pTsdbReadHandle->checkFiles = false;
    }

    // TODO: opt by consider the scan order
    bool ret = doHasDataInBuffer(pTsdbReadHandle);
    terrno = TSDB_CODE_SUCCESS;

    elapsedTime = taosGetTimestampUs() - stime;
    pTsdbReadHandle->cost.checkForNextTime += elapsedTime;
    return ret;
  }
}

// static int32_t doGetExternalRow(STsdbReadHandle* pTsdbReadHandle, int16_t type, SMemTable* pMemRef) {
//  STsdbReadHandle* pSecQueryHandle = NULL;
//
//  if (type == TSDB_PREV_ROW && pTsdbReadHandle->prev) {
//    return TSDB_CODE_SUCCESS;
//  }
//
//  if (type == TSDB_NEXT_ROW && pTsdbReadHandle->next) {
//    return TSDB_CODE_SUCCESS;
//  }
//
//  // prepare the structure
//  int32_t numOfCols = (int32_t) QH_GET_NUM_OF_COLS(pTsdbReadHandle);
//
//  if (type == TSDB_PREV_ROW) {
//    pTsdbReadHandle->prev = taosArrayInit(numOfCols, sizeof(SColumnInfoData));
//    if (pTsdbReadHandle->prev == NULL) {
//      terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
//      goto out_of_memory;
//    }
//  } else {
//    pTsdbReadHandle->next = taosArrayInit(numOfCols, sizeof(SColumnInfoData));
//    if (pTsdbReadHandle->next == NULL) {
//      terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
//      goto out_of_memory;
//    }
//  }
//
//  SArray* row = (type == TSDB_PREV_ROW)? pTsdbReadHandle->prev : pTsdbReadHandle->next;
//
//  for (int32_t i = 0; i < numOfCols; ++i) {
//    SColumnInfoData* pCol = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
//
//    SColumnInfoData colInfo = {{0}, 0};
//    colInfo.info = pCol->info;
//    colInfo.pData = taosMemoryCalloc(1, pCol->info.bytes);
//    if (colInfo.pData == NULL) {
//      terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
//      goto out_of_memory;
//    }
//
//    taosArrayPush(row, &colInfo);
//  }
//
//  // load the previous row
//  SQueryTableDataCond cond = {.numOfCols = numOfCols, .loadExternalRows = false, .type = BLOCK_LOAD_OFFSET_SEQ_ORDER};
//  if (type == TSDB_PREV_ROW) {
//    cond.order = TSDB_ORDER_DESC;
//    cond.twindow = (STimeWindow){pTsdbReadHandle->window.skey, INT64_MIN};
//  } else {
//    cond.order = TSDB_ORDER_ASC;
//    cond.twindow = (STimeWindow){pTsdbReadHandle->window.skey, INT64_MAX};
//  }
//
//  cond.colList = taosMemoryCalloc(cond.numOfCols, sizeof(SColumnInfo));
//  if (cond.colList == NULL) {
//    terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
//    goto out_of_memory;
//  }
//
//  for (int32_t i = 0; i < cond.numOfCols; ++i) {
//    SColumnInfoData* pColInfoData = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
//    memcpy(&cond.colList[i], &pColInfoData->info, sizeof(SColumnInfo));
//  }
//
//  pSecQueryHandle = tsdbQueryTablesImpl(pTsdbReadHandle->pTsdb, &cond, pTsdbReadHandle->idStr, pMemRef);
//  taosMemoryFreeClear(cond.colList);
//
//  // current table, only one table
//  STableCheckInfo* pCurrent = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, pTsdbReadHandle->activeIndex);
//
//  SArray* psTable = NULL;
//  pSecQueryHandle->pTableCheckInfo = createCheckInfoFromCheckInfo(pCurrent, pSecQueryHandle->window.skey, &psTable);
//  if (pSecQueryHandle->pTableCheckInfo == NULL) {
//    taosArrayDestroy(psTable);
//    terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
//    goto out_of_memory;
//  }
//
//
//  tsdbMayTakeMemSnapshot(pSecQueryHandle, psTable);
//  if (!tsdbNextDataBlock((void*)pSecQueryHandle)) {
//    // no result in current query, free the corresponding result rows structure
//    if (type == TSDB_PREV_ROW) {
//      pTsdbReadHandle->prev = doFreeColumnInfoData(pTsdbReadHandle->prev);
//    } else {
//      pTsdbReadHandle->next = doFreeColumnInfoData(pTsdbReadHandle->next);
//    }
//
//    goto out_of_memory;
//  }
//
//  SDataBlockInfo blockInfo = {{0}, 0};
//  tsdbRetrieveDataBlockInfo((void*)pSecQueryHandle, &blockInfo);
//  tsdbRetrieveDataBlock((void*)pSecQueryHandle, pSecQueryHandle->defaultLoadColumn);
//
//  row = (type == TSDB_PREV_ROW)? pTsdbReadHandle->prev:pTsdbReadHandle->next;
//  int32_t pos = (type == TSDB_PREV_ROW)?pSecQueryHandle->cur.rows - 1:0;
//
//  for (int32_t i = 0; i < numOfCols; ++i) {
//    SColumnInfoData* pCol = taosArrayGet(row, i);
//    SColumnInfoData* s = taosArrayGet(pSecQueryHandle->pColumns, i);
//    memcpy((char*)pCol->pData, (char*)s->pData + s->info.bytes * pos, pCol->info.bytes);
//  }
//
// out_of_memory:
//  tsdbCleanupReadHandle(pSecQueryHandle);
//  return terrno;
//}

bool tsdbGetExternalRow(tsdbReaderT pHandle) {
  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)pHandle;
  SQueryFilePos*   cur = &pTsdbReadHandle->cur;

  cur->fid = INT32_MIN;
  cur->mixBlock = true;
  if (pTsdbReadHandle->prev == NULL || pTsdbReadHandle->next == NULL) {
    cur->rows = 0;
    return false;
  }

  int32_t numOfCols = (int32_t)QH_GET_NUM_OF_COLS(pTsdbReadHandle);
  for (int32_t i = 0; i < numOfCols; ++i) {
    SColumnInfoData* pColInfoData = taosArrayGet(pTsdbReadHandle->pResBlock->pDataBlock, i);
    SColumnInfoData* first = taosArrayGet(pTsdbReadHandle->prev, i);

    memcpy(pColInfoData->pData, first->pData, pColInfoData->info.bytes);

    SColumnInfoData* sec = taosArrayGet(pTsdbReadHandle->next, i);
    memcpy(((char*)pColInfoData->pData) + pColInfoData->info.bytes, sec->pData, pColInfoData->info.bytes);

    if (i == 0 && pColInfoData->info.type == TSDB_DATA_TYPE_TIMESTAMP) {
      cur->win.skey = *(TSKEY*)pColInfoData->pData;
      cur->win.ekey = *(TSKEY*)(((char*)pColInfoData->pData) + TSDB_KEYSIZE);
    }
  }

  cur->rows = 2;
  return true;
}

/*
 * if lastRow == NULL, return TSDB_CODE_TDB_NO_CACHE_LAST_ROW
 * else set pRes and return TSDB_CODE_SUCCESS and save lastKey
 */
// int32_t tsdbGetCachedLastRow(STable* pTable, STSRow** pRes, TSKEY* lastKey) {
//  int32_t code = TSDB_CODE_SUCCESS;
//
//  TSDB_RLOCK_TABLE(pTable);
//
//  if (!pTable->lastRow) {
//    code = TSDB_CODE_TDB_NO_CACHE_LAST_ROW;
//    goto out;
//  }
//
//  if (pRes) {
//    *pRes = tdMemRowDup(pTable->lastRow);
//    if (*pRes == NULL) {
//      code = TSDB_CODE_TDB_OUT_OF_MEMORY;
//    }
//  }
//
// out:
//  TSDB_RUNLOCK_TABLE(pTable);
//  return code;
//}

bool isTsdbCacheLastRow(tsdbReaderT* pReader) {
  return ((STsdbReadHandle*)pReader)->cachelastrow > TSDB_CACHED_TYPE_NONE;
}

int32_t checkForCachedLastRow(STsdbReadHandle* pTsdbReadHandle, STableListInfo* tableList) {
  assert(pTsdbReadHandle != NULL && tableList != NULL);

  //  TSKEY    key = TSKEY_INITIAL_VAL;
  //
  //  SArray* group = taosArrayGetP(groupList->pGroupList, 0);
  //  assert(group != NULL);
  //
  //  STableKeyInfo* pInfo = (STableKeyInfo*)taosArrayGet(group, 0);
  //
  //  int32_t code = 0;
  //
  //  if (((STable*)pInfo->pTable)->lastRow) {
  //    code = tsdbGetCachedLastRow(pInfo->pTable, NULL, &key);
  //    if (code != TSDB_CODE_SUCCESS) {
  //      pTsdbReadHandle->cachelastrow = TSDB_CACHED_TYPE_NONE;
  //    } else {
  //      pTsdbReadHandle->cachelastrow = TSDB_CACHED_TYPE_LASTROW;
  //    }
  //  }
  //
  //  // update the tsdb query time range
  //  if (pTsdbReadHandle->cachelastrow != TSDB_CACHED_TYPE_NONE) {
  //    pTsdbReadHandle->window      = TSWINDOW_INITIALIZER;
  //    pTsdbReadHandle->checkFiles  = false;
  //    pTsdbReadHandle->activeIndex = -1;  // start from -1
  //  }

  return TSDB_CODE_SUCCESS;
}

int32_t checkForCachedLast(STsdbReadHandle* pTsdbReadHandle) {
  assert(pTsdbReadHandle != NULL);

  int32_t code = 0;
  //  if (pTsdbReadHandle->pTsdb && atomic_load_8(&pTsdbReadHandle->pTsdb->hasCachedLastColumn)){
  //    pTsdbReadHandle->cachelastrow = TSDB_CACHED_TYPE_LAST;
  //  }

  // update the tsdb query time range
  if (pTsdbReadHandle->cachelastrow) {
    pTsdbReadHandle->checkFiles = false;
    pTsdbReadHandle->activeIndex = -1;  // start from -1
  }

  return code;
}

STimeWindow updateLastrowForEachGroup(STableListInfo* pList) {
  STimeWindow window = {INT64_MAX, INT64_MIN};

  //  int32_t totalNumOfTable = 0;
  //  SArray* emptyGroup = taosArrayInit(16, sizeof(int32_t));
  //
  //  // NOTE: starts from the buffer in case of descending timestamp order check data blocks
  //  size_t numOfGroups = taosArrayGetSize(groupList->pGroupList);
  //  for (int32_t j = 0; j < numOfGroups; ++j) {
  //    SArray* pGroup = taosArrayGetP(groupList->pGroupList, j);
  //    TSKEY   key = TSKEY_INITIAL_VAL;
  //
  //    STableKeyInfo keyInfo = {0};
  //
  //    size_t numOfTables = taosArrayGetSize(pGroup);
  //    for (int32_t i = 0; i < numOfTables; ++i) {
  //      STableKeyInfo* pInfo = (STableKeyInfo*)taosArrayGet(pGroup, i);
  //
  //      // if the lastKey equals to INT64_MIN, there is no data in this table
  //      TSKEY lastKey = 0;  //((STable*)(pInfo->pTable))->lastKey;
  //      if (key < lastKey) {
  //        key = lastKey;
  //
  //        //        keyInfo.pTable  = pInfo->pTable;
  //        keyInfo.lastKey = key;
  //        pInfo->lastKey = key;
  //
  //        if (key < window.skey) {
  //          window.skey = key;
  //        }
  //
  //        if (key > window.ekey) {
  //          window.ekey = key;
  //        }
  //      }
  //    }
  //
  //    // more than one table in each group, only one table left for each group
  //    //    if (keyInfo.pTable != NULL) {
  //    //      totalNumOfTable++;
  //    //      if (taosArrayGetSize(pGroup) == 1) {
  //    //        // do nothing
  //    //      } else {
  //    //        taosArrayClear(pGroup);
  //    //        taosArrayPush(pGroup, &keyInfo);
  //    //      }
  //    //    } else {  // mark all the empty groups, and remove it later
  //    //      taosArrayDestroy(pGroup);
  //    //      taosArrayPush(emptyGroup, &j);
  //    //    }
  //  }
  //
  //  // window does not being updated, so set the original
  //  if (window.skey == INT64_MAX && window.ekey == INT64_MIN) {
  //    window = TSWINDOW_INITIALIZER;
  //    assert(totalNumOfTable == 0 && taosArrayGetSize(groupList->pGroupList) == numOfGroups);
  //  }
  //
  //  taosArrayRemoveBatch(groupList->pGroupList, TARRAY_GET_START(emptyGroup), (int32_t)taosArrayGetSize(emptyGroup));
  //  taosArrayDestroy(emptyGroup);
  //
  //  groupList->numOfTables = totalNumOfTable;
  return window;
}

void tsdbRetrieveDataBlockInfo(tsdbReaderT* pTsdbReadHandle, SDataBlockInfo* pDataBlockInfo) {
  STsdbReadHandle* pHandle = (STsdbReadHandle*)pTsdbReadHandle;
  SQueryFilePos*   cur = &pHandle->cur;

  uint64_t uid = 0;

  // there are data in file
  if (pHandle->cur.fid != INT32_MIN) {
    STableBlockInfo* pBlockInfo = &pHandle->pDataBlockInfo[cur->slot];
    uid = pBlockInfo->pTableCheckInfo->tableId;
  } else {
    STableCheckInfo* pCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
    uid = pCheckInfo->tableId;
  }

  tsdbDebug("data block generated, uid:%" PRIu64 " numOfRows:%d, tsrange:%" PRId64 " - %" PRId64 " %s", uid, cur->rows,
            cur->win.skey, cur->win.ekey, pHandle->idStr);

  pDataBlockInfo->uid = uid;

#if 0
  // for multi-group data query processing test purpose
  pDataBlockInfo->groupId = uid;
#endif

  pDataBlockInfo->rows = cur->rows;
  pDataBlockInfo->window = cur->win;
}

/*
 * return null for mixed data block, if not a complete file data block, the statistics value will always return NULL
 */
int32_t tsdbRetrieveDataBlockStatisInfo(tsdbReaderT* pTsdbReadHandle, SColumnDataAgg*** pBlockStatis, bool* allHave) {
  STsdbReadHandle* pHandle = (STsdbReadHandle*)pTsdbReadHandle;
  *allHave = false;

  SQueryFilePos* c = &pHandle->cur;
  if (c->mixBlock) {
    *pBlockStatis = NULL;
    return TSDB_CODE_SUCCESS;
  }

  STableBlockInfo* pBlockInfo = &pHandle->pDataBlockInfo[c->slot];
  assert((c->slot >= 0 && c->slot < pHandle->numOfBlocks) || ((c->slot == pHandle->numOfBlocks) && (c->slot == 0)));

  // file block with sub-blocks has no statistics data
  if (pBlockInfo->compBlock->numOfSubBlocks > 1) {
    *pBlockStatis = NULL;
    return TSDB_CODE_SUCCESS;
  }

  int64_t stime = taosGetTimestampUs();
  int     statisStatus = tsdbLoadBlockStatis(&pHandle->rhelper, pBlockInfo->compBlock);
  if (statisStatus < TSDB_STATIS_OK) {
    return terrno;
  } else if (statisStatus > TSDB_STATIS_OK) {
    *pBlockStatis = NULL;
    return TSDB_CODE_SUCCESS;
  }

  tsdbDebug("vgId:%d, succeed to load block statis part for uid %" PRIu64, REPO_ID(pHandle->pTsdb),
            TSDB_READ_TABLE_UID(&pHandle->rhelper));

  int16_t* colIds = pHandle->suppInfo.defaultLoadColumn->pData;

  size_t numOfCols = QH_GET_NUM_OF_COLS(pHandle);
  memset(pHandle->suppInfo.plist, 0, numOfCols * POINTER_BYTES);
  memset(pHandle->suppInfo.pstatis, 0, numOfCols * sizeof(SColumnDataAgg));

  for (int32_t i = 0; i < numOfCols; ++i) {
    pHandle->suppInfo.pstatis[i].colId = colIds[i];
  }

  *allHave = true;
  tsdbGetBlockStatis(&pHandle->rhelper, pHandle->suppInfo.pstatis, (int)numOfCols, pBlockInfo->compBlock);

  // always load the first primary timestamp column data
  SColumnDataAgg* pPrimaryColStatis = &pHandle->suppInfo.pstatis[0];
  assert(pPrimaryColStatis->colId == PRIMARYKEY_TIMESTAMP_COL_ID);

  pPrimaryColStatis->numOfNull = 0;
  pPrimaryColStatis->min = pBlockInfo->compBlock->minKey.ts;
  pPrimaryColStatis->max = pBlockInfo->compBlock->maxKey.ts;
  pHandle->suppInfo.plist[0] = &pHandle->suppInfo.pstatis[0];

  // update the number of NULL data rows
  int32_t* slotIds = pHandle->suppInfo.slotIds;
  for (int32_t i = 1; i < numOfCols; ++i) {
    ASSERT(colIds[i] == pHandle->pSchema->columns[slotIds[i]].colId);
    if (IS_BSMA_ON(&(pHandle->pSchema->columns[slotIds[i]]))) {
      if (pHandle->suppInfo.pstatis[i].numOfNull == -1) {  // set the column data are all NULL
        pHandle->suppInfo.pstatis[i].numOfNull = pBlockInfo->compBlock->numOfRows;
      }

      pHandle->suppInfo.plist[i] = &pHandle->suppInfo.pstatis[i];
    } else {
      *allHave = false;
    }
  }

  int64_t elapsed = taosGetTimestampUs() - stime;
  pHandle->cost.statisInfoLoadTime += elapsed;

  *pBlockStatis = pHandle->suppInfo.plist;
  return TSDB_CODE_SUCCESS;
}

SArray* tsdbRetrieveDataBlock(tsdbReaderT* pTsdbReadHandle, SArray* pIdList) {
  /**
   * In the following two cases, the data has been loaded to SColumnInfoData.
   * 1. data is from cache, 2. data block is not completed qualified to query time range
   */
  STsdbReadHandle* pHandle = (STsdbReadHandle*)pTsdbReadHandle;
  if (pHandle->cur.fid == INT32_MIN) {
    return pHandle->pResBlock->pDataBlock;
  } else {
    STableBlockInfo* pBlockInfo = &pHandle->pDataBlockInfo[pHandle->cur.slot];
    STableCheckInfo* pCheckInfo = pBlockInfo->pTableCheckInfo;

    if (pHandle->cur.mixBlock) {
      return pHandle->pResBlock->pDataBlock;
    } else {
      SDataBlockInfo binfo = GET_FILE_DATA_BLOCK_INFO(pCheckInfo, pBlockInfo->compBlock);
      assert(pHandle->realNumOfRows <= binfo.rows);

      // data block has been loaded, todo extract method
      SDataBlockLoadInfo* pBlockLoadInfo = &pHandle->dataBlockLoadInfo;

      if (pBlockLoadInfo->slot == pHandle->cur.slot && pBlockLoadInfo->fileGroup->fid == pHandle->cur.fid &&
          pBlockLoadInfo->uid == pCheckInfo->tableId) {
        return pHandle->pResBlock->pDataBlock;
      } else {  // only load the file block
        SBlock* pBlock = pBlockInfo->compBlock;
        if (doLoadFileDataBlock(pHandle, pBlock, pCheckInfo, pHandle->cur.slot) != TSDB_CODE_SUCCESS) {
          return NULL;
        }

        int32_t numOfRows = doCopyRowsFromFileBlock(pHandle, pHandle->outputCapacity, 0, 0, pBlock->numOfRows - 1);
        return pHandle->pResBlock->pDataBlock;
      }
    }
  }
}

static void* doFreeColumnInfoData(SArray* pColumnInfoData) {
  if (pColumnInfoData == NULL) {
    return NULL;
  }

  size_t cols = taosArrayGetSize(pColumnInfoData);
  for (int32_t i = 0; i < cols; ++i) {
    SColumnInfoData* pColInfo = taosArrayGet(pColumnInfoData, i);
    colDataDestroy(pColInfo);
  }

  taosArrayDestroy(pColumnInfoData);
  return NULL;
}

static void* destroyTableCheckInfo(SArray* pTableCheckInfo) {
  size_t size = taosArrayGetSize(pTableCheckInfo);
  for (int32_t i = 0; i < size; ++i) {
    STableCheckInfo* p = taosArrayGet(pTableCheckInfo, i);
    destroyTableMemIterator(p);

    taosMemoryFreeClear(p->pCompInfo);
  }

  taosArrayDestroy(pTableCheckInfo);
  return NULL;
}

void tsdbCleanupReadHandle(tsdbReaderT queryHandle) {
  STsdbReadHandle* pTsdbReadHandle = (STsdbReadHandle*)queryHandle;
  if (pTsdbReadHandle == NULL) {
    return;
  }

  pTsdbReadHandle->pResBlock->pDataBlock = doFreeColumnInfoData(pTsdbReadHandle->pResBlock->pDataBlock);

  taosArrayDestroy(pTsdbReadHandle->suppInfo.defaultLoadColumn);
  taosMemoryFreeClear(pTsdbReadHandle->pDataBlockInfo);
  taosMemoryFreeClear(pTsdbReadHandle->suppInfo.pstatis);
  taosMemoryFreeClear(pTsdbReadHandle->suppInfo.plist);
  taosMemoryFree(pTsdbReadHandle->suppInfo.slotIds);

  if (!emptyQueryTimewindow(pTsdbReadHandle)) {
    //    tsdbMayUnTakeMemSnapshot(pTsdbReadHandle);
  } else {
    assert(pTsdbReadHandle->pTableCheckInfo == NULL);
  }

  if (pTsdbReadHandle->pTableCheckInfo != NULL) {
    pTsdbReadHandle->pTableCheckInfo = destroyTableCheckInfo(pTsdbReadHandle->pTableCheckInfo);
  }

  tsdbDestroyReadH(&pTsdbReadHandle->rhelper);

  tdFreeDataCols(pTsdbReadHandle->pDataCols);
  pTsdbReadHandle->pDataCols = NULL;

  pTsdbReadHandle->prev = doFreeColumnInfoData(pTsdbReadHandle->prev);
  pTsdbReadHandle->next = doFreeColumnInfoData(pTsdbReadHandle->next);

  SIOCostSummary* pCost = &pTsdbReadHandle->cost;

  tsdbDebug("%p :io-cost summary: head-file read cnt:%" PRIu64 ", head-file time:%" PRIu64 " us, statis-info:%" PRId64
            " us, datablock:%" PRId64 " us, check data:%" PRId64 " us, %s",
            pTsdbReadHandle, pCost->headFileLoad, pCost->headFileLoadTime, pCost->statisInfoLoadTime,
            pCost->blockLoadTime, pCost->checkForNextTime, pTsdbReadHandle->idStr);

  taosMemoryFree(pTsdbReadHandle->idStr);
  taosMemoryFree(pTsdbReadHandle->pSchema);
  taosMemoryFreeClear(pTsdbReadHandle);
}
