CHAPTER 10: TRANSACTION MANAGEMENT AND CONCURRENCY CONTROL

Description

CIS 3365 Quiz on CHAPTER 10: TRANSACTION MANAGEMENT AND CONCURRENCY CONTROL, created by Miguel Lucero on 05/04/2017.
Miguel Lucero
Quiz by Miguel Lucero, updated more than 1 year ago
Miguel Lucero
Created by Miguel Lucero over 7 years ago
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Resource summary

Question 1

Question
1. Most real-world database transactions are formed by only one database request.
Answer
  • True
  • False

Question 2

Question
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.
Answer
  • True
  • False

Question 3

Question
3. The DBMS guarantees that the semantic meaning of a transaction truly represents the real-world event.
Answer
  • True
  • False

Question 4

Question
4. Atomicity indicates the permanence of the database's consistent state.
Answer
  • True
  • False

Question 5

Question
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.
Answer
  • True
  • False

Question 6

Question
6. Incomplete or improper transactions can have a devastating effect on database integrity.
Answer
  • True
  • False

Question 7

Question
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.
Answer
  • True
  • False

Question 8

Question
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.
Answer
  • True
  • False

Question 9

Question
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.
Answer
  • True
  • False

Question 10

Question
10. The scheduler establishes the order in which the operations within concurrent transactions are executed.
Answer
  • True
  • False

Question 11

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

Question 12

Question
12. A lock guarantees the open use of a data item to multiple transactions.
Answer
  • True
  • False

Question 13

Question
13. In a page-level lock, the DBMS will lock an entire diskpage.
Answer
  • True
  • False

Question 14

Question
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.
Answer
  • True
  • False

Question 15

Question
15. A shared lock produces no conflict as long as all the concurrent transactions are read-write only.
Answer
  • True
  • False

Question 16

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

Question 17

Question
17. Timestamps must only have the single property of uniqueness.
Answer
  • True
  • False

Question 18

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

Question 19

Question
19. An optimistic approach is based on the assumption that the majority of the database operations do not conflict.
Answer
  • True
  • False

Question 20

Question
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.
Answer
  • True
  • False

Question 21

Question
21. The serializable isolation level is the least restrictive level defined by the ANSI SQL standard.
Answer
  • True
  • False

Question 22

Question
22. The reason for the different levels of isolation is to increase transaction concurrency.
Answer
  • True
  • False

Question 23

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

Question 24

Question
24. The last step in the write-through technique recovery procedure is to identify the last checkpoint in the transaction log.
Answer
  • True
  • False

Question 25

Question
25. A transaction is a unit of work that must be either entirely completed or aborted.
Answer
  • a. timed
  • b. practical
  • c. logical
  • d. physical

Question 26

Question
26. A consistent database state is .
Answer
  • 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

Question 27

Question
27. requires that all operations of a transaction be completed.
Answer
  • a. Specificity
  • b. Atomicity
  • c. Durability
  • d. Time stamping

Question 28

Question
28. means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.
Answer
  • a. Serializability
  • b. Atomicity
  • c. Isolation
  • d. Time stamping

Question 29

Question
29. A single-user database system automatically ensures of the database, because only one transaction is executed at a time.
Answer
  • a. serializability and durability
  • b. atomicity and isolation
  • c. serializability and isolation
  • d. atomicity and serializability

Question 30

Question
30. The ANSI has defined standards that govern SQL database transactions. Transaction support is provided by two SQL statements: and ROLLBACK
Answer
  • a. RETRIEVE
  • b. ASSIGN
  • c. UPDATE
  • d. COMMIT

Question 31

Question
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?
Answer
  • 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.

Question 32

Question
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?
Answer
  • 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.

Question 33

Question
33. The implicit beginning of a transaction is .
Answer
  • 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

Question 34

Question
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.
Answer
  • a. data dictionary
  • b. metadata
  • c. rollback manager
  • d. transaction log

Question 35

Question
35. One of the three most common data integrity and consistency problems is .
Answer
  • a. lost updates
  • b. disk failures
  • c. user errors
  • d. deadlocks

Question 36

Question
36. occurs when a transaction accesses data before and after one or more other transactions finish working with such data.
Answer
  • a. Inconsistent retrievals
  • b. The phenomena of uncommitted data
  • c. Lost update problems
  • d. Dirty read problems

Question 37

Question
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.
Answer
  • a. shared
  • b. common
  • c. unrelated
  • d. locked

Question 38

Question
38. are required to prevent another transaction from reading inconsistent data.
Answer
  • a. Locks
  • b. Schedules
  • c. Stamps
  • d. Logs

Question 39

Question
39. The______ manager is responsible for assigning and policing the locks used by the transactions.
Answer
  • a. transaction
  • b. database
  • c. lock
  • d. schedule

Question 40

Question
40. Lock indicates the level of lock use.
Answer
  • a. granularity
  • b. shrinking
  • c. growing
  • d. serializability

Question 41

Question
41. A lock locks the entire table preventing access to any row by a transaction while another transaction is using the table.
Answer
  • a. database-level
  • b. table-level
  • c. page-level
  • d. row-level

Question 42

Question
42. A lock locks the entire diskpage.
Answer
  • a. transaction-level
  • b. table-level
  • c. page-level
  • d. row-level

Question 43

Question
43. A diskpage, or page, is the equivalent of a .
Answer
  • a. database table
  • b. disk sector
  • c. database schema
  • d. diskblock

Question 44

Question
44. A lock allows concurrent transactions to access different rows of the same table.
Answer
  • a. database-level
  • b. table-level
  • c. page-level
  • d. row-level

Question 45

Question
45. A(n) specifically reserves access to the transaction that locked the object.
Answer
  • a. shared lock
  • b. exclusive lock
  • c. binary lock
  • d. deadlock

Question 46

Question
46. A(n) lock exists when concurrent transactions are granted read access on the basis of a common lock
Answer
  • a. shared
  • b. exclusive
  • c. binary
  • d. two-phase

Question 47

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

Question 48

Question
48. A(n) phase in a two-phase lock is when a transaction releases all locks and cannot obtain any new lock.
Answer
  • a. growing
  • b. shrinking
  • c. locking
  • d. unlocking

Question 49

Question
49. A(n) condition occurs when two or more transactions wait for each other to unlock data.
Answer
  • a. deadlock
  • b. exclusive lock
  • c. binary lock
  • d. two-phase lock

Question 50

Question
50. The approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.
Answer
  • a. scheduled
  • b. table-locking
  • c. unique
  • d. timestamping

Question 51

Question
51. In the wait/die scheme,:
Answer
  • 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.

Question 52

Question
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.
Answer
  • a. read
  • b. validation
  • c. write
  • d. shared

Question 53

Question
53. In the optimistic approach, during the phase, changes are permanently applied to the database.
Answer
  • a. read
  • b. validation
  • c. write
  • d. shared

Question 54

Question
54. The isolation level ensures that queries return consistent results.
Answer
  • a. Read Uncommitted
  • b. Read Committed
  • c. Serializable
  • d. Repeatable Read

Question 55

Question
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.
Answer
  • a. phantom read
  • b. dirty read
  • c. uncommitted dependency
  • d. nonrepeatable read
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