Explanation: If the operation inserted an entry in a B+-tree, the undo information U would indicate that a deletion operation is to be performed, and would identify the B+-tree and what entry to delete from the tree. Such logging of information about operations is called logical logging. 4. Redo operations are performed exclusively using
A. Logical logging
B. Physical logging
C. Physical log records
D. Both b and c
Answer:A
Explanation: If the operation inserted an entry in a B+-tree, the undo information U would indicate that a deletion operation is to be performed, and would identify the B+-tree and what entry to delete from the tree. Such logging of information about operations is called logical logging. 4. Redo operations are performed exclusively using
A. Logical logging B. Physical logging C. Physical log records D. Both b and c
Explanation: Logging of old-value and new-value information is called physical logging. 5. To perform logical redo or undo, the database state on disk must be operation _____________, that is, it should not have partial effects of any operation.