A.A leaf will be marked as invalid.
B.An update in a leaf row takes place.
C.The index will be updated automatically at commit.
D.A leaf row in the index will be deleted and inserted.
E.The index becomes invalid when you make any updates.

A.It is generated by using the redo log files. 
B.It helps in row-level recovery from user errors.
C.It can be performed to recover ALTER TABLE statements 
D.It fails when undo data pertaining to the transaction is overwritten.
E.The database has to be opened with the resetlogs option after performing Flashback Query.