A.by using the SQL access advisor
B.by using the Automatic Workload Repository report
C.by running the Automatic Database Diagnostic Monitor （ADDM）
D.by using the Automatic Workload Repository Compare Period report
E.by analyzing the output of the V$ACTIVE_SESSION_HISTORY view

A.It is recommended for the columns that have unique values.
B.It can be converted to a B-tree index by using the ALTER INDEX command.
C.It has a bitmap segment for each distinct value in the key column， containing a string of bits in which each bit represents the presence or absence of a key column value.
D.Updating the key column locks the whole bitmap segment that contains the bit for the key value to be updated.