IBM Mainframe Online Test

Consider the following COBOL program:

What will the program display when it is executed?

Consider the following pseudocode snippet in COBOL:

After executing this program, what will be the final state of StrArr?

Consider the following COBOL code snippet. The program aims to read from a VSAM Key-Sequenced Data Set (KSDS) named 'CUSTOMER-FILE' which contains customer records. The program reads the file in ascending order by 'CUSTOMER-ID', performs some processing (not shown here), and then displays the 'CUSTOMER-NAME' of the last record read.

Assuming there are no syntax errors and the 'CUSTOMER-FILE' is present and accessible, what will the program display as the last customer's name after executing this COBOL program?

A: The program will display the name of the customer with the highest 'CUSTOMER-ID'.
B: The program will display the name of the customer with the lowest 'CUSTOMER-ID'.
C: The program will not display any customer name.
D: The program will display the name of the first customer in the 'CUSTOMER-FILE'.
E: The program will display an uninitialized or random 'LAST-NAME'.

Consider the following DB2 database scenario. You are managing a stock trading platform that uses a DB2 database to track user transactions and market prices. The database has two tables, Users and Stocks.

A user transaction to buy a stock is a two-step process:

1. Decrease the user's balance in the Users table.
2. Increase the quantity of the stock owned by the user in the Stocks table.

Both these steps need to be performed atomically to maintain data consistency.

Recently, with the increase in the volume of transactions, you are experiencing performance issues. Additionally, you have observed that during peak trading hours, a large number of user transactions are getting blocked, leading to user dissatisfaction.

Which of the following strategies would BEST address the performance and blocking issues, while ensuring data consistency?

A: Implement an optimistic concurrency control mechanism.
B: Reduce the transaction isolation level to READ UNCOMMITTED.
C: Break the transaction into two separate transactions
D: Increase the database's buffer pool size.
E: Implement row-level locking.

Consider two users executing the following transactions concurrently on DB2:

Transaction 1 (User A):

Transaction 2 (User B):

Table1 has thousands of records, and the value 'Value1' for Column1 is not unique in Table1. Both transactions are executed almost simultaneously with Transaction 2 executed a bit earlier. Considering the isolation levels set for the transactions, which of the following is the potential data inconsistency issue that might arise?

A: A deadlock situation may occur.
B: Transaction 1 will wait indefinitely for Transaction 2 to commit.
C: Both transactions might update the same record leading to a lost update.
D: Transaction 1 can experience a dirty read due to the changes made by Transaction 2.

You are managing a DB2 database which includes a table named `ORDERS`. The `ORDERS` table has a large volume of data and contains the following columns: `OrderID`, `CustomerID`, `OrderDate`, `ProductID`, `Quantity`. 

One of the frequently executed queries on the `ORDERS` table is:

You are asked to optimize this query without changing its structure or the table schema. Which of the following strategies would MOST likely improve the performance of this query?

A: Create a HASH index on `CustomerID` and `OrderDate`.
B: Create a CLUSTERED index on `CustomerID` and `OrderDate`.
C: Create a NONCLUSTERED index on `CustomerID` and `OrderDate`.
D: Create a CLUSTERED index on `OrderID`.
E: Create a NONCLUSTERED index on `OrderID`.

Consider the following pseudocode in an IBM DB2 environment:

This stored procedure is used to update the inventory of a particular item. If the `NewQuantity` input parameter is negative, the procedure signals an exception. There's also a handler declared for exceptions, which logs an error message.

Given this scenario, if an error occurs during the UPDATE statement, which of the following will happen?

A: The update operation will fail, an error message will be logged, and the quantity in the inventory will remain unchanged.
B: The update operation will succeed, no error message will be logged, and the quantity in the inventory will be updated.
C: The update operation will fail, an error message will be logged, but the quantity in the inventory will still be updated.
D: The update operation will fail, no error message will be logged, and the quantity in the inventory will remain unchanged.
E: The update operation will succeed, an error message will be logged, but the quantity in the inventory will still be updated.

Consider the following JCL snippet:

In MYJOB, PROG1 in STEP1 uses the dataset MY.DS.INPUT with a disposition of (OLD,DELETE,KEEP). PROG2 in STEP2 also uses the dataset MY.DS.INPUT with a disposition of (NEW,PASS,DELETE).

Assume that STEP1 executed successfully, but STEP2 failed during its execution. What would be the status of the dataset MY.DS.INPUT after the job MYJOB is run?

A: MY.DS.INPUT will be deleted.
B: MY.DS.INPUT will be kept and can be used by other jobs.
C: MY.DS.INPUT will be newly created.
D: MY.DS.INPUT will be available for the duration of the job, then deleted.
E: MY.DS.INPUT status cannot be determined with the provided information.

Consider a JCL job that needs to execute five steps: STEP01, STEP02, STEP03, STEP04, and STEP05. The steps represent data initialization, data processing, data validation, error handling, and job finalization respectively.

The execution rules are as follows:

1. The job should always start with STEP01.
2. STEP02 should only execute if STEP01 completes successfully with a return code (RC) of 0.
3. STEP03 should always run after STEP02, irrespective of STEP02's return code.
4. STEP04 should only execute if either STEP02 or STEP03 fails, i.e., return a code not equal to 0.
5. STEP05 should always be the last step, and should only execute if all the previous steps were successful (each returning a code of 0).

Given these rules, how would you design the JCL job using the IF/THEN/ELSE/ENDIF construct?