【多选题】You need to ensure that the database users should be able to use the various flashback query features in order to go back in time by four hours. What would you do to achieve this?()
A.
set SQL_TRACE=True
B.
set UNDO_RETENTION=14400
C.
set FAST_START_MTTR_TARGET=240
D.
set LOG_CHECKPOINT_INTERVAL=240
E.
set DB_FLASHBACK_RETENTION_TARGET=14400
F.
set the RETENTION GUARANTEE clause for the undo tablespace
【单选题】Following the Harvard scandal, Mary Miller, the former dean of students at Yale, made an impassioned appeal to her school's professors to refrain from takehome exams. “Students risk health and well be...
A.
Elderly students find it hard to keep up with the rapid changes in education.
B.
Some believe take-home exams may affect students' performance in other courses.
C.
Certain professors believe in-class exams are ultimately more helpful to students.
D.
In-class exams are believed to discourage cheating in exams.
E.
The author was happy to learn she could do some exams at home.
F.
Students who put off their work until the last moment often find the exams more difficult than they actually are.
G.
Different students may prefer different types of exams.