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  1. A distributed database is which of the following?

  2. A.

     A single logical database that is spread to multiple locations and is interconnected by a network

    B.

     A loose collection of file that is spread to multiple locations and is interconnected by a network

    C.

     A single logical database that is limited to one location.

    D.

     A loose collection of file that is limited to one location.


  3. A semijoin is which of the following?

  4. A.

     Only the joining attributes are sent from one site to another and then all of the rows are returned.

    B.

     All of the attributes are sent from one site to another and then only the required rows are returned.

    C.

     Only the joining attributes are sent from one site to another and then only the required rows are returned.

    D.

     All of the attributes are sent from one site to another and then only the required rows are returned.


  5. Which of the following is a disadvantage of replication?

  6. A.

     Reduced network traffic

    B.

     If the database fails at one site, a copy can be located at another site.

    C.

     Each site must have the same storage capacity.

    D.

     Each transaction may proceed without coordination across the network.


  7. A distributed database can use which of the following strategies?

  8. A.

     Totally centralized at one location and accessed by many sites

    B.

     Partially or totally replicated across sites

    C.

     Partitioned into segments at different sites

    D.

     All of the above


  9. Which of the following is not one of the stages in the evolution of distributed DBMS?

  10. A.

     Unit of work

    B.

     Remote unit of work

    C.

     Distributed unit of Work

    D.

     Distributed request


  11. With failure transparency, all of the actions of a transaction are committed or none of them are committed.

  12. A.

     True

    B.

     False


  13. Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system.

  14. A.

     True

    B.

     False


  15. Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.

  16. A.

     True

    B.

     False


  17. Synchronization for pull replication is less disruptive and occurs only when needed by each site, not when a central master site thinks it is best to update.

  18. A.

     True

    B.

     False


  19. With asynchronous technology, if any copy of a data item is updated anywhere on the network, the same update is immediately applied to all other copies or it is aborted.

  20. A.

     True

    B.

     False