diff --git a/source/dnode/vnode/src/tsdb/tsdbRead2.c b/source/dnode/vnode/src/tsdb/tsdbRead2.c
index cafa232462e3e48316a0ec96f6e361244fe07960..f90969bcaa18b32b0cfb73f6d4ab1c1e58a8e41c 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead2.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead2.c
@@ -967,14 +967,53 @@ static void cleanupTableScanInfo(SReaderStatus* pStatus) {
 
     doCleanupTableScanInfo(*px);
   }
+}
+
+typedef struct SBrinRecordIter {
+  SArray*   pBrinBlockList;
+  SBrinBlk* pCurrentBlk;
+  int32_t   blockIndex;
+  int32_t   recordIndex;
+  SDataFileReader* pReader;
+  SBrinBlock block;
+  SBrinRecord record;
+} SBrinRecordIter;
+
+void initBrinRecordIter(SBrinRecordIter* pIter, SDataFileReader* pReader, SArray* pList) {
+  memset(&pIter->block, 0, sizeof(SBrinBlock));
+  memset(&pIter->record, 0, sizeof(SBrinRecord));
+  pIter->blockIndex = -1;
+  pIter->recordIndex = -1;
+
+  pIter->pReader = pReader;
+  pIter->pBrinBlockList = pList;
+}
+
+SBrinRecord* getNextBrinRecord(SBrinRecordIter* pIter) {
+  if (pIter->blockIndex == -1 || (pIter->recordIndex + 1) >= TARRAY2_SIZE(pIter->block.numRow)) {
+    pIter->blockIndex += 1;
+    if (pIter->blockIndex >= taosArrayGetSize(pIter->pBrinBlockList)) {
+      return NULL;
+    }
+
+    pIter->pCurrentBlk = taosArrayGet(pIter->pBrinBlockList, pIter->blockIndex);
+
+    tBrinBlockClear(&pIter->block);
+    tsdbDataFileReadBrinBlock(pIter->pReader, pIter->pCurrentBlk, &pIter->block);
+    pIter->recordIndex = -1;
+  }
 
-//  pStatus->mapDataCleaned = true;
+  pIter->recordIndex += 1;
+  tBrinBlockGet(&pIter->block, pIter->recordIndex, &pIter->record);
+  return &pIter->record;
+}
+
+void clearBrinBlockIter(SBrinRecordIter* pIter) {
+  tBrinBlockDestroy(&pIter->block);
 }
 
 static int32_t doLoadFileBlock(STsdbReader* pReader, SArray* pIndexList, SBlockNumber* pBlockNum, SArray* pTableScanInfoList) {
   size_t  sizeInDisk = 0;
-  size_t  numOfBlocks = taosArrayGetSize(pIndexList);
-
   int64_t st = taosGetTimestampUs();
   cleanupTableScanInfo(&pReader->status);
 
@@ -982,26 +1021,40 @@ static int32_t doLoadFileBlock(STsdbReader* pReader, SArray* pIndexList, SBlockN
   int32_t i = 0, k = 0;
   int32_t numOfTables = tSimpleHashGetSize(pReader->status.pTableMap);
 
-  while(i < numOfBlocks && k < numOfTables) {
-    SBrinBlk* pBlk = taosArrayGet(pIndexList, i);
-    uint64_t uid = pReader->status.uidList.tableUidList[k];
+  int32_t     step = ASCENDING_TRAVERSE(pReader->order) ? 1 : -1;
+  STimeWindow w = pReader->window;
+
+  SBrinRecordIter iter = {0};
+  initBrinRecordIter(&iter, pReader->pFileReader, pIndexList);
+  SBrinRecord* pRecord = NULL;
 
-    SBrinBlock block = {0};
-    tsdbDataFileReadBrinBlock(pReader->pFileReader, pBlk, &block);
+  while (k < numOfTables) {
+    pRecord = getNextBrinRecord(&iter);
 
-//    tMapDataReset(&pScanInfo->mapData);
-//    tsdbReadDataBlk(pReader->pFileReader, pBlockIdx, &pScanInfo->mapData);
-//    taosArrayEnsureCap(pScanInfo->pBlockList, pScanInfo->mapData.nItem);
+    uint64_t uid = pReader->status.uidList.tableUidList[k];
+    if (pRecord == NULL || pRecord->suid > pReader->suid) {
+      break;
+    }
 
-// todo set the correct size
-    sizeInDisk += 0;//pScanInfo->mapData.nData;
+    if (pRecord->suid < pReader->suid) {
+      continue;
+    }
 
-    int32_t     step = ASCENDING_TRAVERSE(pReader->order) ? 1 : -1;
-    STimeWindow w = pReader->window;
-    if (isEmptyQueryTimeWindow(&w)) {
+    ASSERT(pRecord->suid == pReader->suid);
+    if (pRecord->uid < uid) {
       continue;
     }
 
+    while (pRecord->uid > uid && k < numOfTables) {
+      k += 1;
+    }
+
+    if (k >= numOfTables) {
+      break;
+    }
+
+    ASSERT(pRecord->suid == pReader->suid && uid == pRecord->uid);
+
     STableBlockScanInfo* pScanInfo = getTableBlockScanInfo(pReader->status.pTableMap, uid, pReader->idStr);
     if (ASCENDING_TRAVERSE(pReader->order)) {
       w.skey = pScanInfo->lastKey + step;
@@ -1009,69 +1062,39 @@ static int32_t doLoadFileBlock(STsdbReader* pReader, SArray* pIndexList, SBlockN
       w.ekey = pScanInfo->lastKey + step;
     }
 
-    SBrinRecord record = {0};
-    for (int32_t j = 0; j < TARRAY2_SIZE(block.numRow); ++j) {
-      tBrinBlockGet(&block, j, &record);
-      if (record.suid < pReader->suid) {
-        continue;
-      }
-
-      if (record.suid > pReader->suid) {
-        break;
-      }
-
-      {
-        while (record.uid > uid && (k + 1) < numOfTables) {
-          k += 1;
-          uid = pReader->status.uidList.tableUidList[k];
-          pScanInfo = getTableBlockScanInfo(pReader->status.pTableMap, uid, pReader->idStr);
-
-          if (ASCENDING_TRAVERSE(pReader->order)) {
-            w.skey = pScanInfo->lastKey + step;
-          } else {
-            w.ekey = pScanInfo->lastKey + step;
-          }
-        }
-
-        if (k >= numOfTables) {
-          break;
-        }
-
-        if (record.uid < uid) {
-          continue;
-        }
-      }
-
-      ASSERT(record.suid == pReader->suid);
-
-      // 1. time range check
-      if (record.firstKey > w.ekey || record.lastKey < w.skey) {
-        continue;
-      }
-
-      // 2. version range check
-      if (record.firstKeyVer > pReader->verRange.maxVer || record.lastKeyVer < pReader->verRange.minVer) {
-        continue;
-      }
+    if (isEmptyQueryTimeWindow(&w)) {
+      k += 1;
+      continue;
+    }
 
-//      SBlockIndex bIndex = {.ordinalIndex = j, .inFileOffset = record.blockOffset};
-//      bIndex.window = (STimeWindow){.skey = record.firstKey, .ekey = record.lastKey};
-      void* p1 = taosArrayPush(pScanInfo->pBlockList, &record);
-      if (p1 == NULL) {
-        return TSDB_CODE_OUT_OF_MEMORY;
-      }
+    // 1. time range check
+    if (pRecord->firstKey > w.ekey || pRecord->lastKey < w.skey) {
+      continue;
+    }
 
-      pBlockNum->numOfBlocks += 1;
+    // 2. version range check
+    if (pRecord->firstKeyVer > pReader->verRange.maxVer || pRecord->lastKeyVer < pReader->verRange.minVer) {
+      continue;
     }
 
-    i += 1;
+    void* p1 = taosArrayPush(pScanInfo->pBlockList, pRecord);
+    if (p1 == NULL) {
+      return TSDB_CODE_OUT_OF_MEMORY;
+    }
 
-    STableBlockScanInfo** p = taosArrayGetLast(pTableScanInfoList);
-    if ((p == NULL || (*p)->uid != uid) && taosArrayGetSize(pScanInfo->pBlockList) > 0) {
+    pBlockNum->numOfBlocks += 1;
+    if (taosArrayGetSize(pTableScanInfoList) == 0) {
       taosArrayPush(pTableScanInfoList, &pScanInfo);
+    } else {
+      STableBlockScanInfo** p = taosArrayGetLast(pTableScanInfoList);
+      if ((*p)->uid != uid) {
+        taosArrayPush(pTableScanInfoList, &pScanInfo);
+      }
     }
   }
 
+  clearBrinBlockIter(&iter);
+
   pBlockNum->numOfLastFiles = pReader->status.pCurrentFileset->lvlArr->size;
   int32_t total = pBlockNum->numOfLastFiles + pBlockNum->numOfBlocks;
 
@@ -1336,7 +1359,6 @@ static int32_t copyBlockDataToSDataBlock(STsdbReader* pReader) {
 
   SBlockData*         pBlockData = &pStatus->fileBlockData;
   SFileDataBlockInfo* pBlockInfo = getCurrentBlockInfo(pBlockIter);
-//  SDataBlk*           pBlock = getCurrentBlock(pBlockIter);
   SSDataBlock*        pResBlock = pReader->resBlockInfo.pResBlock;
   int32_t             numOfOutputCols = pSupInfo->numOfCols;
   int32_t             code = TSDB_CODE_SUCCESS;