Db2cert6v8 Sample

DB2 UDB 8.1 Family Fundamentals

DB2 Concurrency: Sample Questions 1) Which isolation level would lock the most data? a. Uncommitted Read b. Repeatable Read c. Cursor Stability d. Read Stability 2) An application is bound using repeatable read. You notice that there are a large number of locks being held at any given time, what should you do to decrease the number of locks? a. Increase the size of the locklist parameter b. Use the BIND option to change the isolation level to read stability c. Increase the size of the log files d. Alter the table in question to row level locking 3) If you want to maximize concurrency without seeing uncommitted data values and high data stability is not required. Which isolation level would you choose? a. Uncommitted Read b. Read Stability c. Cursor Stability d. Repeatable Read 4) If you are executing queries and do not want to see changes made to the result data sets produced. Which isolation level would you choose? a. Uncommitted Read b. Read Stability c. Cursor Stability d. Repeatable Read 5) Mary from HR is revising salary of all the staff in the XYZ company. Her application is designed to commit the transaction only after the salary updates from the employee table are made for every employee. At the same time, Peter from the Accounting department uses CS isolation level to query the employee. However, due to Mary’s update, Peter’s application was hung. Which of the following can be set to cause Peter’s application to fail with an error so that he doesn’t have to wait forever? a. b. c. d.

Alter the employee table to use locksize TABLE Increase the value of locklist Update the locktimeout parameter to finite number Decrease the value of maxlock

DB2 Concurrency: Sample Questions

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DB2 UDB 8.1 Family Fundamentals

6) What is the possible cause of a lock escalation? Choose all that apply. a. When lock storage space is full b. An application with too frequent COMMIT and/or ROLLBACK requests c. An application has exceeded the threshold of how much lock storage space each application can hold d. All of the above 7) Which of the following isolation level will avoid phantom reads? a. Uncommitted Read b. Cursor Stability c. Read Stability d. Repeatable Read 8) What does SQL0911N with reason code “2” means? a. The application is timed out due to excessive lock wait b. The application is terminated due to deadlock c. Row locks held by the application are escalated d. The lock storage space is full e. db2user does not have any privilege on the employee table 9) Which of the following object can be explicitly locked by a DB2 command? a. Views b. Buffer pools c. Columns d. Tables 10) Isolation level can be specified for which of the following? a. A session b. A database connection c. A cursor d. All of the above

DB2 Concurrency: Sample Questions

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DB2 UDB 8.1 Family Fundamentals Answers: 1. b 2. b 3. c 4. d 5. c 6. a,c 7. d 8. b 9. d 10. d (You can declare a cursor for a select statement which specifies the isolation level)

DB2 Concurrency: Sample Questions

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