2012年2月11日星期六

Answer these brain-teasers

Thser brain teasers have been tried for years...

Brain-Teasers Part 1:=
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1. Persistency of business data refers to which of the following?

a. Business data are kept in the computer main memory
b. Business data are saved on stable storage such as magnetic disks for the life of the business
c. Business data are saved on stable storage such as magnetic disks for as long as it is needed by the business
d. Once the business data has been saved, its values never change

2. DBMS recovery management deals with

a. restoring the database after a failure.
b. fixing a bad sector in the disk.
c. recovering passwords forgotten by users.
d. getting computers back online after a power outage.

3. Which of the following is neither a characteristic nor a feature of databases?

a. Many users can use the same database at the same time.
b. Relationships provide information connecting different entities.
c. Only one user at a time can access data from the database.
d. Access to data is facilitated by nonprocedural access.

4. Which one of the following is the least likely to be viewed as a transaction?

a. Retrieving an employee hiring date.
b. Transferring $1000 from a customer's savings account to the customer's checking account.
c. Reserving a seat on a train .
d. Reserving a hotel room.

5. A null value indicates:

a. A numeric value with value 0.
b. The absence of a value.
c. A very small value.
d. An erroneous value.

6. In general denormalization produces __________________.

a. more joins
b. a slower system response
c. less data redundancy
d. faster performance

7. All parts of a transaction must be successfully completed to prevent ____________.

a. slow transaction execution
b. data integrity problems
c. concurrency control
d. referential integrity problems

8. A _________________ is one in which all data integrity constraints are satisfied.

a. 2NF
b. completed database design
c. consistent retrieval
d. consistent database state

9. When a transaction is completed, the database reaches a consistent state, and that state cannot be lost, even in the event of the systems failure. That property is referred to as ________________.

a. Atomicity
b. Durability
c. Isolation
d. Serializability

10. Which of the following is important in multi-user and distributed databases to maintain database integrity, where several transactions are likely to be executed concurrently?

a. Structural independence
b. Distribution independence
c. Serializability
d. Isolation

11. In a _______________ client server system, the clients request may be handled by several different intermediate servers.

a. centalized
b. n-tier
c. 2-tier
d. 3-tier

12. A(n) ___________ client is one that conducts a minimum of processing on the client side.

a. loaded
b. push
c. thin
d. end-user

13. Which of the following statements is true when comparing XML to HTML.

a. HTML is more similar to SGML than XML
b. HTML is human readable and uses tags to mark up documents while XML is not.
c. HTML is to displaying content as to XML is describing content.
d. HTML can only display static content whereas XML can display dynamic content.

14. The scheduler ______________ the execution of database operations to ensure serializaility.

a. intermittently sequences
b. interleaves
c. randomly alternates
d. concurrently schedules

15. In this technique for dealing with deadlocks, the DBMS periodically tests the database for deadlocks and if a deadlock is found, the victim is aborted and the other transaction continues?

a. Deadlock avoidance
b. Deadlock detection
c. Two-phase deadlock protocol
d. Deadlock prevention

16. The most common aspects examined in DBMS ______________ are use of indexes, query-optimization algorithms, and management of storage resources.

a. System support
b. Backup and recovery
c. Performance tuning
d. Security monitoring

17. Authorization management defines access control procedures, which allow the DBA to ____________________.

a. Create audit trails to pinpoint violations.
b. Assign passwords to each user.
c. Assign access privileges to specific users to access specific databases.
d. Place limits on the use of DBMS query and reporting tools.

18. Why is the selection of proper field names very important?

a. Because standards exist and must be followed.
b. Because the data structure becomes self-documenting
c. Because record names depend on field names
d. Because it promotes inconsistencies between departments

19. Which of the following is not a statement type in SQL?

a. Database design
b. Database definition
c. Database manipulation
d. Database control

20. In the "three schema architecture", views belong to:

a. The internal level
b. The conceptual level
c. The external level
d. The client-server level

21. Which one of the following indicates poor data quality?

a. The business rule that an employee must belong to a department is enforced by the database
b. The same supplier is shown with two different addresses in two parts of the database
c. Two similar items have two different prices in the supermarket and in the database
d. New prices in a supermarket are updated in a timely fashion in the database

22. Which one of the following is true about the connection between database design and systems development?

a. Database design and systems development are broadly independent
b. Database design and systems development are loosely coupled
c. Database design and systems development are strongly coupled
d. Database design and systems development are totally independent
23. A goal of normalization is to:

a. minimize the number of relationships
b. minimize the number of entities
c. minimize the number of tables
d. minimize data redundancy

29. Durability of a transaction means the following:

a. All changes that took place during a transaction, including temporary changes, are permanently kept
b. Once a transaction is successfully completed, changes resulting from it are stored in the database on permanent storage
c. The results of a transaction are stored forever in the database
d. The effects of atomicity and consistency are durable
Answer: B Level: Medium Page: 420-421

30. Which of the following is an example of lost update?

a. The system assigns the last aisle seat on a flight to John whereas Peter receives a window seat, although both indicated preference for an aisle seat
b. John and Peter receive each a window seat as they both requested
c. John is initially assigned the last window seat, but this seat is later on assigned to Peter
d. None of the above

31. As the bank audit transaction reads Mary's savings balance, $100, Mary transfers $50 to her checking, making it $250, and the audit transaction completes with the combined value of $350 in both accounts. This is called:

a. An uncommitted dependency
b. An incorrect summary
c. A lost update
d. A data entry error

32. Julia has a lock on the savings account and Bill is trying to perform a conflicting action on the data:

a. Bill's transaction is granted permission to perform the desired action
b. Bill's transaction must wait until Julia's lock is released
c. Bill's transaction must wait until Julia has read the savings account value
d. None of the above

33. Julia has a shared lock on the savings account and Bill is trying to perform an action requesting a shared lock on the same data:

a. Bill's transaction is granted permission to perform the desired action
b. Bill's transaction must wait until Julia's lock is released
a. Bill's transaction must wait until Julia has read the savings account value
b. None of the above

34. Julia has an exclusive lock on the savings account and Bill is trying to perform an action requesting a shared lock on the same data:

a. Bill's transaction is granted permission to perform the desired action
b. Bill's transaction must wait until Julia's lock is released
c. Bill's transaction must wait until Julia has read the savings account value
d. None of the above

35. In the two-phase locking protocol:

a. A transaction only acquires a lock after the previously acquired lock has been released
b. A transaction acquires locks as needed. After it starts releasing locks, it does not acquire new locks
c. A transaction acquires all needed locks at once, then releases them after completion
d. The transaction locks the full database, then releases the locks


36. In the optimistic approach for concurrency control:

a. Only shared locks are used
b. Deadlocks are always detected before they occur
c. Only exclusive locks are used
d. Locks are not used

Thank you..

Indiawhat is this, some kind of homework assignment?

1. Persistency of business data refers to which of the following?
- computer salesmen who won't leave you alone

2. DBMS recovery management deals with
- when your database crashes, is your rsum up to date

3. Which of the following is neither a characteristic nor a feature of databases?
- strawberry marmelade

4. Which one of the following is the least likely to be viewed as a transaction?
- the VP of Accounting doesn't like your expense report item for the hooker you hired on your last trip overseas

5. A null value indicates:
- there's nothing there -- not even a null value!

6. In general denormalization produces __________________.
- that bloated feeling; try Tums

7. All parts of a transaction must be successfully completed to prevent ____________.
- the VP of Accounting from coming to see you about your long term career prospects

8. A _________________ is one in which all data integrity constraints are satisfied.
- data integrity straightjacket

9. When a transaction is completed, the database reaches a consistent state, and that state cannot be lost, even in the event of the systems failure. That property is referred to as ________________.
- job security

10. Which of the following is important in multi-user and distributed databases to maintain database integrity, where several transactions are likely to be executed concurrently?
- an up-to-date patch from Microsoft

11. In a _______________ client server system, the clients request may be handled by several different intermediate servers.
- blue-sky in-your-dreams client-server system

12. A(n) ___________ client is one that conducts a minimum of processing on the client side.
- polite

13. Which of the following statements is true when comparing XML to HTML.
- well, they have ML in common, so i guess they are both markup languages, eh

14. The scheduler ______________ the execution of database operations to ensure serializaility.
- ties the noose for

15. In this technique for dealing with deadlocks, the DBMS periodically tests the database for deadlocks and if a deadlock is found, the victim is aborted and the other transaction continues?
- dance hall or reggae, you choose

oh, you said deadlock, not dreadlock -- my bad

16. The most common aspects examined in DBMS ______________ are use of indexes, query-optimization algorithms, and management of storage resources.
- senior year college courses, after crappy query design was taught in the first three years

17. Authorization management defines access control procedures, which allow the DBA to ____________________.
- take the occasional trip to Thailand

18. Why is the selection of proper field names very important?
- because with improper field names, you will run afoul of the censors

19. Which of the following is not a statement type in SQL?
- SELECT COUNT(*) FROM USERS WHERE CLUE IS NOT NULL
--> 0 rows returned

20. In the "three schema architecture", views belong to:
- anybody who has an opinion, especially about the third schema

21. Which one of the following indicates poor data quality?
- your paycheque is never the same from week to week and sometimes the deductions exceed the gross pay

22. Which one of the following is true about the connection between database design and systems development?
- unless the DBAs have full authority, the developers will always design a crappy database

23. A goal of normalization is to:
- produce stable and worthwhile members of society

HEY, WHERE DID QUESTIONS 24 THROUGH 28 GO???

29. Durability of a transaction means the following:
- you can just throw it in the washer and dryer on the "Normal" cycle

30. Which of the following is an example of lost update?
- The Raiders of the Next SuperBowl

31. As the bank audit transaction reads Mary's savings balance, $100, Mary transfers $50 to her checking, making it $250, and the audit transaction completes with the combined value of $350 in both accounts. This is called:
- Mary's been working the streets again

32. Julia has a lock on the savings account and Bill is trying to perform a conflicting action on the data:
- Julia should just punch him in the stomach

33. Julia has a shared lock on the savings account and Bill is trying to perform an action requesting a shared lock on the same data:
- okay, she should try hoofing him in the stones

34. Julia has an exclusive lock on the savings account and Bill is trying to perform an action requesting a shared lock on the same data:
- okay, now she's really mad, here she comes with the frying pan...

35. In the two-phase locking protocol:
- you have a dead-bolt AND a chain

36. In the optimistic approach for concurrency control:
- you are on the street looking for a DBA job where they don't ask you tough questions like these

rudy
http://r937.com/|||rudy, that is the funniest thing I've seen since watching The Daily Show with John Stewart last night.

:D

blindman|||LOL

*

Falling off bar stool...umm office chair...|||If Julia has a shared lock, can Bill attempt a pass-through query?

I think Julia ought to give Bill a break, or at least credit for being persistent. He's probably a very nice guy.

blindman|||Originally posted by blindman
If Julia has a shared lock, can Bill attempt a pass-through query?

I think Julia ought to give Bill a break, or at least credit for being persistent. He's probably a very nice guy.

blindman

Is that a shared lock on a chastity belt? Is that why Bill wants to attempt a pass thru?

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