All technological notes.
Flashback Transaction QueryFlashback Transaction QueryFlashback Transaction Query:
view FLASHBACK_TRANSACTION_QUERY:

DDL commands are seen as dictionary updates.
data dictionary.Flashback Transaction Query on a transaction underlying a DDL command displays the changes made to the data dictionary. 一条 DDL 命令的 tran query 体现字典的改变Dropped objects appear as object numbers.
Dropped users appear as user identifiers.
user ID only, and not the username.如果执行交易的用户被删除了, 只会显示用户 ID 而不是用户名.