Thursday, 22 May 2014

Distributed database - Quiz 1

Distributed Database - Quiz 1


1. Let us suppose that in a distributed database, during a transaction T1, one of the sites, say S1, is failed. When recovers, the site S1 has to check its log file (log based recovery) to decide the next move on the transaction T1. If the log contains a record, what the site S1 has to do?
    Need not do anything
    Perform Undo
    Perform Redo
    Abort the transaction

2. Global Wait-for graph is used for ________________ in Distributed database.
    Handling concurrency control
    Handling failures
    Handling deadlock
    None of the above

3. In Distributed database, ______________ are the transactions for which a log is found in the log file, but neither a log nor an log is found.
    In-doubt transactions
    Serialized transactions
    Cascadeless transactions
    Distributed transactions

4. While using commit protocols for handling atomicity issues, the distributed database system may enter into a situation called Blocking problem. Which of the following commit protocols can avoid Blocking problem?
    Two-phase commit protocol
    Three-phase commit protocol
    Both of the above
    None of the above

5. Which of the following concurrency control protocol is suitable for an application where frequency of read operation is much greater than that of write operation?
    Majority protocol
    Quorum-consensus protocol
    Biased protocol
    Single lock protocol

6. Which of the following parallel database architectures is/are mainly used by distributed database system?
    Shared Memory
    Shared Disk
    Shared Nothing
    Hierarchical

7. Which of the following is not a promise of distributed database?
    Network Transparency
    Replication Transaparency
    Fragmentation Transparency
    None of the above

8. All sites in a distributed database must commit at exactly the same instant. TRUE/FALSE
    TRUE
    FALSE

9. The real use of the Two-phase commit protocol is ______________
    Deadlock will not occur
    Concurrency control can be avoided
    Atomicity, i.e, all-or-nothing commits at all sites
    None of the above

10. Read one, write all available protocol is used to increase ___________ in a distributed database system.
    Availability
    Robustness
    Both Availability and Robustness
    Neither Availability nor Robustness

Score =

Correct answers:

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