Recently I was working on a VLDB on the implementation of a disaster recovery environment configured with data guard physical standby and fast start failover.

One of the questions that come up was about the overhead of truncating and dropping tables. There are daily jobs on the database that truncate extremely large partitions, and as note 565535.1 explains, we knew there is an overhead for these operations.

But the information on the note was not clear enough, we the additional information I've got from Senior Oracle colleagues I did compile this document "Impact of Truncate or Drop Table When Flashback Database is Enabled" that further explain the case