Explanation:Operations such as inserting an entry into a B+-tree may not be idempotent, and the recovery algorithm must therefore make sure that an operation that has already been performed is not performed again. 7. Immediate database modification technique uses
A. Both undo and redo
B. Undo but no redo
C. Redo but no undo
D. Neither undo nor redo
Answer:A
Explanation:Operations such as inserting an entry into a B+-tree may not be idempotent, and the recovery algorithm must therefore make sure that an operation that has already been performed is not performed again. 7. Immediate database modification technique uses
A. Both undo and redo B. Undo but no redo C. Redo but no undo D. Neither undo nor redo
Explanation:Undo erases all the changes and redo makes the deleted changes. 8. Shadow paging has