Questions from Database Systems

Q: Rewrite the preceding query, but also ensure that you include only

Rewrite the preceding query, but also ensure that you include only instructors who have given at least one other non-null grade in some course.

Q: In the ARIES recovery algorithm: a. If at the

In the ARIES recovery algorithm: a. If at the beginning of the analysis pass, a page is not in the checkpoint dirty page table, will we need to apply any redo records to it? Why? b. What is Rec LSN, a...

Q: Explain the difference between a system crash and a “disaster.”

Explain the difference between a system crash and a “disaster.”

Q: For each of the following requirements, identify the best choice of

For each of the following requirements, identify the best choice of degree of durability in a remote backup system: a. Data loss must be avoided, but some loss of availability may be tolerated. b. Tra...

Q: Stable storage cannot be implemented. a. Explain why it

Stable storage cannot be implemented. a. Explain why it cannot be. b. Explain how database systems deal with this problem

Q: Redesign the database of Exercise 8.4 into first normal form

Redesign the database of Exercise 8.4 into first normal form and fourth normal form. List any functional or multivalued dependencies that you assume. Also list all referential-integrity constraints tha...

Q: Explain how the database may become inconsistent if some log records pertaining

Explain how the database may become inconsistent if some log records pertaining to a block are not output to stable storage before the block is output to disk.

Q: Outline the drawbacks of the no-steal and force buffer management

Outline the drawbacks of the no-steal and force buffer management policies.

Q: Suppose two-phase locking is used, but exclusive locks are

Suppose two-phase locking is used, but exclusive locks are released early, that is, locking is not done in a strict two-phase manner. Give an example to show why transaction rollback can result in a w...

Q: Physiological redo logging can reduce logging overheads significantly, especially with a

Physiological redo logging can reduce logging overheads significantly, especially with a slotted page record organization. Explain why.