@Override
  public void queryForDeviceRegionScan(
      IDeviceID deviceID,
      boolean isAligned,
      long ttlLowerBound,
      Map<String, List<IChunkMetadata>> chunkMetadataMap,
      Map<String, List<IChunkHandle>> memChunkHandleMap,
      List<Pair<ModEntry, IMemTable>> modsToMemTabled) {

    Map<IDeviceID, IWritableMemChunkGroup> memTableMap = getMemTableMap();

    // check If MemTable Contains this path
    if (!memTableMap.containsKey(deviceID)) {
      return;
    }

    IWritableMemChunkGroup writableMemChunkGroup = memTableMap.get(deviceID);
    if (isAligned) {
      getMemAlignedChunkHandleFromMemTable(
          deviceID,
          (AlignedWritableMemChunkGroup) writableMemChunkGroup,
          chunkMetadataMap,
          memChunkHandleMap,
          ttlLowerBound,
          modsToMemTabled);
    } else {
      getMemChunkHandleFromMemTable(
          deviceID,
          (WritableMemChunkGroup) writableMemChunkGroup,
          chunkMetadataMap,
          memChunkHandleMap,
          ttlLowerBound,
          modsToMemTabled);
    }
  }
Create this MemChunk if it's not exist.

@param deviceId device id
@param schemaList measurement schemaList
@return this MemChunkGroup
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/memtable/AbstractMemTable.java