@Override
  public long ramBytesUsed() {
    return INSTANCE_SIZE + deviceID.ramBytesUsed() + seriesPath.ramBytesUsed();
  }
Return true if taking first page reader from seq readers
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/source/SeriesScanUtil.java