As may be clear later, the database doesn't actually have to write the do, Undo, and state records to its log just yet, although it might.

稍后就会清楚，实际上数据库也不需要马上把do、Undo、和状态记录写入它的日志，尽管可以这么做。

youdao

Database-2 writes Undo and do records and state to its recovery log, again just as Database-1 did.

Database - 2把Undo和do记录及状态写入它的恢复日志，再次像Database - 1做的一样。

youdao

In the event of a system failure, transaction log recovery can apply or undo only those transactions not written to disk at the time of the failure.

在系统失败时，事务日志可以应用或取消失败时没有写入磁盘的那些事务。

youdao