MCQOPTIONS
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MCQOPTIONS
This section includes 30 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 2. |
A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 3. |
The purpose of timestamping is to avoid the use of locks. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 4. |
The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 5. |
The problem of concurrency control is more complex in a distributed database. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 6. |
An increasingly popular option for data distribution as well as for fault tolerance of any database is to store a separate copy of the database at each of two or more sites. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 7. |
The semijoin approach saves network traffic. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 8. |
Asynchronous technology can result in unsatisfactorily slow response time because the distributed DBMS is spending considerable time checking that an update is accurately and completely propagated across the network. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 9. |
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. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 10. |
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. |
| Answer» C. A different DBMS is used at each location and data are not distributed across all nodes. | |
| 11. |
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. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 12. |
Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» C. 1 | |
| 13. |
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 |
| Answer» B. Remote unit of work | |
| 14. |
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. |
| Answer» D. Each transaction may proceed without coordination across the network. | |
| 15. |
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. |
| Answer» D. All of the attributes are sent from one site to another and then only the required rows are returned. | |
| 16. |
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 |
| Answer» E. | |
| 17. |
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. |
| Answer» C. The required data are at one local site and the distributed DBMS passes the request to only the local DBMS. | |
| 18. |
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. |
| Answer» D. All of the above. | |
| 19. |
Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 20. |
Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 21. |
Data replication is favored where most process requests are read-only and where the data are relatively static. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 22. |
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 |
| Answer» B. Horizontal Partitioning | |
| 23. |
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. |
| Answer» E. | |
| 24. |
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. |
| Answer» B. A loose collection of file that is spread to multiple locations and is interconnected by a network | |
| 25. |
With failure transparency, all of the actions of a transaction are committed or none of them are committed. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 26. |
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. |
| Answer» E. | |
| 27. |
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 |
| Answer» D. Horizontal and Vertical Partitioning | |
| 28. |
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. |
| Answer» E. | |
| 29. |
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. |
| Answer» B. The same DBMS is at each node and a central DBMS coordinates database access. | |
| 30. |
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 |
| Answer» E. | |