每个应用程序系统在把修改提交给本地系统之后，把更新(常常是以批处理模式)发送给引用主数据系统。

Each application system sends out, often in batch mode, updates to the referential master data system (long) after the changes are committed to the local system.

youdao

出现这种情况的原因如下：元数据更新删除了对原先数据块的任何引用，却指向磁盘上没有填充过数据的数据块。

Here's why this could happen: the metadata update would erase any reference to the original data block(s), but would point to data block(s) on disk that were never filled with data.

youdao

虽然这意味着数据永远不会写入到位(从来没有被覆盖)，而是写入新块并更新元数据来引用数据。

This means that data is never written in place (never overwritten), but instead new blocks are written and the metadata updated to reference it.

youdao