Monday, December 1, 2014

Distributed Databases

1. 
A distributed database has which of the following advantages over a centralized database?
A.Software cost
B.Software complexity
C.Slow Response
D.Modular growth
2. 
An autonomous homogenous environment is which of the following?
A.The same DBMS is at each node and each DBMS works independently.
B.The same DBMS is at each node and a central DBMS coordinates database access.
C.A different DBMS is at each node and each DBMS works independently.
D.A different DBMS is at each node and a central DBMS coordinates database access.
3. 
A transaction manager is which of the following?
A.Maintains a log of transactions
B.Maintains before and after database images
C.Maintains appropriate concurrency control
D.All of the above.
4. 
Location transparency allows for which of the following?
A.Users to treat the data as if it is at one location
B.Programmers to treat the data as if it is at one location
C.Managers to treat the data as if it is at one location
D.All of the above.
5. 
A heterogeneous distributed database is which of the following?
A.The same DBMS is used at each location and data are not distributed across all nodes.
B.The same DBMS is used at each location and data are distributed across all nodes.
C.A different DBMS is used at each location and data are not distributed across all nodes.
D.A different DBMS is used at each location and data are distributed across all nodes.

6. 
Some of the columns of a relation are at different sites is which of the following?
A.Data Replication
B.Horizontal Partitioning
C.Vertical Partitioning
D.Horizontal and Vertical Partitioning
7. 
Which of the following is true concerning a global transaction?
A.The required data are at one local site and the distributed DBMS routes requests as necessary.
B.The required data are located in at least one nonlocal site and the distributed DBMS routes requests as necessary.
C.The required data are at one local site and the distributed DBMS passes the request to only the local DBMS.
D.The required data are located in at least one nonlocal site and the distributed DBMS passes the request to only the local DBMS.
8. 
A homogenous distributed database is which of the following?
A.The same DBMS is used at each location and data are not distributed across all nodes.
B.The same DBMS is used at each location and data are distributed across all nodes.
C.A different DBMS is used at each location and data are not distributed across all nodes.
D.A different DBMS is used at each location and data are distributed across all nodes.
9. 
Replication should be used when which of the following exist?
A.When transmission speeds and capacity in a network prohibit frequent refreshing of large tables.
B.When using many nodes with different operating systems and DBMSs and database designs.
C.The application's data can be somewhat out-of-date.
D.All of the above.
10. 
Storing a separate copy of the database at multiple locations is which of the following?
A.Data Replication
B.Horizontal Partitioning
C.Vertical Partitioning
D.Horizontal and Vertical Partitioning

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