You have a production instance running on your server. UNDO_RETENTION is not long
enough to satisfy read-consistency requirements. How do you change the
UNDO_RETENTION value?
A.
by executing UPDATE.. statement on V$PARAMETER to change the value of
UNDO_RETENTION
B.
by executing the ALTER SYSTEM .. command
C.
by re-creating the control file with a new value for UNDO_RETENTION
D.
by executing the ALTER DATABASE.. command in the MOUNT state
Hello,
B is the best answer for this.
Ref: https://docs.oracle.com/cd/B28359_01/server.111/b28310/undo003.htm#ADMIN11465
>>
..
Change UNDO_RETENTION at any time using the ALTER SYSTEM statement:
ALTER SYSTEM SET UNDO_RETENTION = 2400;
…
<<
Thank
Vin