Miguel Lucero
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CIS 3365 Quiz on CHAPTER 10: TRANSACTION MANAGEMENT AND CONCURRENCY CONTROL, created by Miguel Lucero on 05/04/2017.

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Miguel Lucero
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CHAPTER 10: TRANSACTION MANAGEMENT AND CONCURRENCY CONTROL

CHAPTER 10: TRANSACTION MANAGEMENT AND CONCURRENCY CONTROL

Question 1 of 55

1

1. Most real-world database transactions are formed by only one database request.

Select one of the following:

  • True
  • False

Explanation

Question 2 of 55

1

2. Although the DBMS is designed to recover a database to a previous consistent state when an interruption prevents the completion of a required set of transactions, the transactions themselves are defined by the end user or programmer and must be semantically correct.

Select one of the following:

  • True
  • False

Explanation

Question 3 of 55

1

3. The DBMS guarantees that the semantic meaning of a transaction truly represents the real-world event.

Select one of the following:

  • True
  • False

Explanation

Question 4 of 55

1

4. Atomicity indicates the permanence of the database's consistent state.

Select one of the following:

  • True
  • False

Explanation

Question 5 of 55

1

5. Serializability means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.

Select one of the following:

  • True
  • False

Explanation

Question 6 of 55

1

6. Incomplete or improper transactions can have a devastating effect on database integrity.

Select one of the following:

  • True
  • False

Explanation

Question 7 of 55

1

7. Durability requires that all portions of the transaction must be treated as a single, logical unit of work in which all operations are applied and completed to produce a consistent database.

Select one of the following:

  • True
  • False

Explanation

Question 8 of 55

1

8. The multiuser DBMS must implement controls to ensure serializability and isolation of transactions, in addition to atomicity and durability, in order to guard the database's consistency and integrity.

Select one of the following:

  • True
  • False

Explanation

Question 9 of 55

1

9. The phenomenon of uncommitted data occurs when two transactions are executed concurrently and the first transaction is rolled back after the second transaction has already accessed the uncommitted data—thus violating the isolation property of transactions.

Select one of the following:

  • True
  • False

Explanation

Question 10 of 55

1

10. The scheduler establishes the order in which the operations within concurrent transactions are executed.

Select one of the following:

  • True
  • False

Explanation

Question 11 of 55

1

11. A scheduler facilitates data isolation to ensure that two transactions do not update the same data element at the same time.

Select one of the following:

  • True
  • False

Explanation

Question 12 of 55

1

12. A lock guarantees the open use of a data item to multiple transactions.

Select one of the following:

  • True
  • False

Explanation

Question 13 of 55

1

13. In a page-level lock, the DBMS will lock an entire diskpage.

Select one of the following:

  • True
  • False

Explanation

Question 14 of 55

1

14. A field-level lock allows concurrent transactions to access the same row, as long as they require the use of different fields within that row.

Select one of the following:

  • True
  • False

Explanation

Question 15 of 55

1

15. A shared lock produces no conflict as long as all the concurrent transactions are read-write only.

Select one of the following:

  • True
  • False

Explanation

Question 16 of 55

1

16. A growing phase in a two-phase lock is when a transaction acquires all the required locks without locking any data.

Select one of the following:

  • True
  • False

Explanation

Question 17 of 55

1

17. Timestamps must only have the single property of uniqueness.

Select one of the following:

  • True
  • False

Explanation

Question 18 of 55

1

18. Time stamping demands a lot of system resources because many transactions might have to be stopped, rescheduled, and stamped.

Select one of the following:

  • True
  • False

Explanation

Question 19 of 55

1

19. An optimistic approach is based on the assumption that the majority of the database operations do not conflict.

Select one of the following:

  • True
  • False

Explanation

Question 20 of 55

1

20. When using an optimistic approach, during the read phase, a transaction reads the database, executes the needed computations, and makes the updates to a private copy of the database values.

Select one of the following:

  • True
  • False

Explanation

Question 21 of 55

1

21. The serializable isolation level is the least restrictive level defined by the ANSI SQL standard.

Select one of the following:

  • True
  • False

Explanation

Question 22 of 55

1

22. The reason for the different levels of isolation is to increase transaction concurrency.

Select one of the following:

  • True
  • False

Explanation

Question 23 of 55

1

23. The transaction recovery write-ahead-log protocol ensures that transaction logs are always written before any database data are actually updated.

Select one of the following:

  • True
  • False

Explanation

Question 24 of 55

1

24. The last step in the write-through technique recovery procedure is to identify the last checkpoint in the transaction log.

Select one of the following:

  • True
  • False

Explanation

Question 25 of 55

1

25. A transaction is a unit of work that must be either entirely completed or aborted.

Select one of the following:

  • a. timed

  • b. practical

  • c. logical

  • d. physical

Explanation

Question 26 of 55

1

26. A consistent database state is .

Select one of the following:

  • a. one in which all tables have foreign keys

  • b. one in which all data integrity constraints are satisfied

  • c. one in which all tables are normalized

  • d. one in which all SQL statements only update one table at a time

Explanation

Question 27 of 55

1

27. requires that all operations of a transaction be completed.

Select one of the following:

  • a. Specificity

  • b. Atomicity

  • c. Durability

  • d. Time stamping

Explanation

Question 28 of 55

1

28. means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.

Select one of the following:

  • a. Serializability

  • b. Atomicity

  • c. Isolation

  • d. Time stamping

Explanation

Question 29 of 55

1

29. A single-user database system automatically ensures of the database, because only one transaction is executed at a time.

Select one of the following:

  • a. serializability and durability

  • b. atomicity and isolation

  • c. serializability and isolation

  • d. atomicity and serializability

Explanation

Question 30 of 55

1

30. The ANSI has defined standards that govern SQL database transactions. Transaction support is provided by two SQL statements: and ROLLBACK

Select one of the following:

  • a. RETRIEVE

  • b. ASSIGN

  • c. UPDATE

  • d. COMMIT

Explanation

Question 31 of 55

1

31. ANSI defines four events that signal the end of a transaction. Of the following events, which is defined by ANSI as being equivalent to a COMMIT?

Select one of the following:

  • a. Five SQL statements are executed.

  • b. The end of a program is successfully reached.

  • c. The program is abnormally terminated.

  • d. The database is shut down for maintenance.

Explanation

Question 32 of 55

1

32. ANSI defines four events that signal the end of a transaction. Of the following events, which is defined by ANSI as being equivalent to a ROLLBACK?

Select one of the following:

  • a. Five SQL statements are executed.

  • b. The end of a program is successfully reached.

  • c. The program is abnormally terminated.

  • d. The database is shut down for maintenance.

Explanation

Question 33 of 55

1

33. The implicit beginning of a transaction is .

Select one of the following:

  • a. when the database is started

  • b. when a table is accessed for the first time

  • c. when the first SQL statement is encountered

  • d. when the COMMIT command is issued

Explanation

Question 34 of 55

1

34. The information stored in the is used by the DBMS for a recovery requirement triggered by a ROLLBACK statement, a program’s abnormal termination, or a system failure such as a network discrepancy or a disk crash.

Select one of the following:

  • a. data dictionary

  • b. metadata

  • c. rollback manager

  • d. transaction log

Explanation

Question 35 of 55

1

35. One of the three most common data integrity and consistency problems is .

Select one of the following:

  • a. lost updates

  • b. disk failures

  • c. user errors

  • d. deadlocks

Explanation

Question 36 of 55

1

36. occurs when a transaction accesses data before and after one or more other transactions finish working with such data.

Select one of the following:

  • a. Inconsistent retrievals

  • b. The phenomena of uncommitted data

  • c. Lost update problems

  • d. Dirty read problems

Explanation

Question 37 of 55

1

37. As long as two transactions, T1 and T2, access data, there is no conflict, and the order of execution is irrelevant to the final outcome.

Select one of the following:

  • a. shared

  • b. common

  • c. unrelated

  • d. locked

Explanation

Question 38 of 55

1

38. are required to prevent another transaction from reading inconsistent data.

Select one of the following:

  • a. Locks

  • b. Schedules

  • c. Stamps

  • d. Logs

Explanation

Question 39 of 55

1

39. The______ manager is responsible for assigning and policing the locks used by the transactions.

Select one of the following:

  • a. transaction

  • b. database

  • c. lock

  • d. schedule

Explanation

Question 40 of 55

1

40. Lock indicates the level of lock use.

Select one of the following:

  • a. granularity

  • b. shrinking

  • c. growing

  • d. serializability

Explanation

Question 41 of 55

1

41. A lock locks the entire table preventing access to any row by a transaction while another transaction is using the table.

Select one of the following:

  • a. database-level

  • b. table-level

  • c. page-level

  • d. row-level

Explanation

Question 42 of 55

1

42. A lock locks the entire diskpage.

Select one of the following:

  • a. transaction-level

  • b. table-level

  • c. page-level

  • d. row-level

Explanation

Question 43 of 55

1

43. A diskpage, or page, is the equivalent of a .

Select one of the following:

  • a. database table

  • b. disk sector

  • c. database schema

  • d. diskblock

Explanation

Question 44 of 55

1

44. A lock allows concurrent transactions to access different rows of the same table.

Select one of the following:

  • a. database-level

  • b. table-level

  • c. page-level

  • d. row-level

Explanation

Question 45 of 55

1

45. A(n) specifically reserves access to the transaction that locked the object.

Select one of the following:

  • a. shared lock

  • b. exclusive lock

  • c. binary lock

  • d. deadlock

Explanation

Question 46 of 55

1

46. A(n) lock exists when concurrent transactions are granted read access on the basis of a common lock

Select one of the following:

  • a. shared

  • b. exclusive

  • c. binary

  • d. two-phase

Explanation

Question 47 of 55

1

47. What is a rule that applies to the two-phase locking protocol?

Select one of the following:

  • a. Two transactions cannot have conflicting locks.

  • b. No unlock operation can precede a lock operation in a different transaction

  • c. No data is affected until all locks are released.

  • d. No data is affected until the transaction is in its locked position

Explanation

Question 48 of 55

1

48. A(n) phase in a two-phase lock is when a transaction releases all locks and cannot obtain any new lock.

Select one of the following:

  • a. growing

  • b. shrinking

  • c. locking

  • d. unlocking

Explanation

Question 49 of 55

1

49. A(n) condition occurs when two or more transactions wait for each other to unlock data.

Select one of the following:

  • a. deadlock

  • b. exclusive lock

  • c. binary lock

  • d. two-phase lock

Explanation

Question 50 of 55

1

50. The approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.

Select one of the following:

  • a. scheduled

  • b. table-locking

  • c. unique

  • d. timestamping

Explanation

Question 51 of 55

1

51. In the wait/die scheme,:

Select one of the following:

  • a. the older transaction rolls back the younger transaction and reschedules it.

  • b. the younger, preempted transaction is rescheduled using the same time stamp.

  • c. the older transaction waits for the younger one to complete and release its locks.

  • d. both the younger and older transactions wait indefinitely to be released.

Explanation

Question 52 of 55

1

52. In the optimistic approach, during the phase, a transaction scans the database, executes the needed computations, and makes the updates to a private copy of the database values.

Select one of the following:

  • a. read

  • b. validation

  • c. write

  • d. shared

Explanation

Question 53 of 55

1

53. In the optimistic approach, during the phase, changes are permanently applied to the database.

Select one of the following:

  • a. read

  • b. validation

  • c. write

  • d. shared

Explanation

Question 54 of 55

1

54. The isolation level ensures that queries return consistent results.

Select one of the following:

  • a. Read Uncommitted

  • b. Read Committed

  • c. Serializable

  • d. Repeatable Read

Explanation

Question 55 of 55

1

55. A(n) occurs when a transaction executes a query at time t1, and then it runs the same query at time t2, yielding additional rows that satisfy the query.

Select one of the following:

  • a. phantom read

  • b. dirty read

  • c. uncommitted dependency

  • d. nonrepeatable read

Explanation

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