@Override
  public synchronized void syncPageBuffer() {
    super.syncPageBuffer();
    for (Map.Entry<Short, ISegment<ByteBuffer, ICachedMNode>> entry : segCacheMap.entrySet()) {
      entry.getValue().syncBuffer();
    }

    pageBuffer.position(SchemaFileConfig.PAGE_LENGTH - memberNum * SchemaFileConfig.SEG_OFF_DIG);
    for (short offset : segOffsetLst) {
      ReadWriteIOUtils.write(offset, pageBuffer);
    }
  }
Implementing marking deletion will not modify {@linkplain #memberNum} nor truncate {@linkplain
#segOffsetLst}.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/pbtree/schemafile/SegmentedPage.java