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