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This section includes 37 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A transaction is a series of actions to be taken on the database so that either all of them are performed successfully or none of them are performed at all. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 2. |
Locks placed by command are implicit locks. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 3. |
A point of synchronization between the database and the transaction log is generally referred to as a stop point. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 4. |
In optimistic locking, the assumption is made that conflict will occur. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 5. |
A phantom read occurs when a transaction rereads data it has previously read and finds modifications or deletions caused by a committed transaction. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 6. |
The transaction log contains a copy of every database record (or page) after it has changed. These records are called before images. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 7. |
Locks placed by the DBMS are explicit locks. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 8. |
Database administration refers to a function that applies to the entire organization. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 9. |
The lost update problem is when User A reads data that have been processed by a portion of a transaction from User B. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 10. |
The size of a lock is referred to as lock sizing. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 11. |
When two transactions are being processed against the database at the same time they are termed concurrent transactions. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 12. |
An exclusive lock locks the item from change but not from read. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 13. |
An ACID transaction is one that is atomic, consistent isolated, and durable. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 14. |
A transaction in which either all of the database actions occur or none of them do is called: |
| A. | atomic. |
| B. | consistent. |
| C. | isolated. |
| D. | durable. |
| Answer» B. consistent. | |
| 15. |
Which of the following occurs when one transaction reads a changed record that has not been committed to the database? |
| A. | Nonrepeatable read |
| B. | Phantom read |
| C. | Dirty read |
| D. | Consistent read |
| Answer» D. Consistent read | |
| 16. |
A cursor type in which the application can only move forward through the recordset is called: |
| A. | forward only. |
| B. | static. |
| C. | keyset. |
| D. | dynamic. |
| Answer» B. static. | |
| 17. |
The goal of database security is to ensure that only authorized users can perform authorized activities at authorized times. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 18. |
The size of the lock is referred to as the lock granularity. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 19. |
The overall responsibility of the DBA is to facilitate the development and use of the database. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 20. |
The advantage of optimistic locking is that: |
| A. | the lock is obtained only after the transaction has processed. |
| B. | the lock is obtained before the transaction has processed. |
| C. | the lock never needs to be obtained. |
| D. | transactions that are best suited are those with a lot of activity. |
| Answer» B. the lock is obtained before the transaction has processed. | |
| 21. |
Two transactions that run concurrently and generate results that are consistent with the results that would have occurred if they had run separately are referred to as serializable transactions. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 22. |
When one transaction reads a changed record that has not been committed to the database a filthy read occurs. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» C. 1 | |
| 23. |
The size of a lock is called: |
| A. | implicit lock. |
| B. | lock granularity. |
| C. | exclusive lock. |
| D. | shared lock. |
| Answer» C. exclusive lock. | |
| 24. |
A durable transaction is one in which all committed changes are permanent. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 25. |
Locks placed by the DBMS are called ________ . |
| A. | implicit locks |
| B. | explicit locks |
| C. | exclusive locks |
| D. | shared locks |
| Answer» B. explicit locks | |
| 26. |
Which of the following allows dirty reads, nonrepeatable reads and phantom reads to occur? |
| A. | Read committed |
| B. | Read uncommitted |
| C. | Repeatable read |
| D. | Serializable |
| Answer» C. Repeatable read | |
| 27. |
A cursor type in which the application sees the data as they were at the time the cursor was opened is called: |
| A. | forward only. |
| B. | static. |
| C. | keyset. |
| D. | dynamic. |
| Answer» C. keyset. | |
| 28. |
Which of the following disallows both dirty reads and nonrepeatable reads, but allows phantom reads? |
| A. | Read committed |
| B. | Read uncommitted |
| C. | Repeatable read |
| D. | Serializable |
| Answer» D. Serializable | |
| 29. |
Which of the following refers to a cursor type where changes of any type and from any source are visible? |
| A. | Forward only |
| B. | Static |
| C. | Keyset |
| D. | Dynamic |
| Answer» E. | |
| 30. |
In this instance, dirty reads are disallowed, while nonrepeatable reads and phantom reads are allowed. |
| A. | Read committed |
| B. | Read uncommitted |
| C. | Repeatable read |
| D. | Serializable |
| Answer» B. Read uncommitted | |
| 31. |
Which of the following locks the item from change but not from read? |
| A. | Implicit lock |
| B. | Explicit lock |
| C. | Exclusive lock |
| D. | Shared lock |
| Answer» E. | |
| 32. |
Which of the following occurs when a transaction rereads data and finds new rows that were inserted by a command transaction since the prior read? |
| A. | Nonrepeatable read |
| B. | Phantom read |
| C. | Dirty read |
| D. | Consistent read |
| Answer» C. Dirty read | |
| 33. |
Which of the following locks the item from access of any type? |
| A. | Implicit lock |
| B. | Explicit lock |
| C. | Exclusive lock |
| D. | Shared lock |
| Answer» D. Shared lock | |
| 34. |
Dirty read, nonrepeatable, and phantom reads are not possible in this instance. |
| A. | Read committed |
| B. | Read uncommitted |
| C. | Repeatable read |
| D. | Serializable |
| Answer» E. | |
| 35. |
A transaction for which all committed changes are permanent is called: |
| A. | atomic. |
| B. | consistent. |
| C. | isolated. |
| D. | durable. |
| Answer» E. | |
| 36. |
Resource locking is a process to prevent multiple applications from obtaining copies of the same record when the record is about to be changed. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 37. |
Locks placed by command are called ________ . |
| A. | implicit locks |
| B. | explicit locks |
| C. | exclusive locks |
| D. | shared locks |
| Answer» C. exclusive locks | |