11. A distributed database is which of the following?

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.

12. A semijoin is which of the following?

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.

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

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.

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

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

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

A. Unit of work
B. Remote unit of work
C. Distributed Unit of Work
D. Distributed request