What is the difference between primary key & unique index ?

Correct Answer: While allocating KSDS Datasets, free space is declared at regular intervals at the time of initial loading This is done because this free space is utilized for keeping the data arranged in sequence physically, even though inserted randomly

Correct Answer: COMMIT statements are used to release locks which are required for that unit of work, and then permit a new unit of work In other words, if COMMITS are not coded in the program and the program has been sent for execution, then while processing, in place of just going back to a few inserts since the nearest commit, the program has to go back to the inserts which were made during the entire run of the program This extra process takes around twice or thrice the time taken normally

Correct Answer: It can be done by setting the record length?s size to more than half of the page?s size

Correct Answer: -1 indicates the field is null 0 indicates the field is not null -2 indicates the field is truncated

Correct Answer: CURSOR STABILITY: - CS is a row level locking - Acquires an exclusive lock on the row that is to be updated - When the control is moved to the next updatable row, the lock is released REPEATABLE READ: - RR is a page level locking - Acquires an exclusive lock on the entire page which is the source of row availability - When the control is moved to the next updatable page the lock is released

Correct Answer: GROUP BY partitions the selected rows on the distinct values of the column on which you group by HAVING selects GROUPs which match the criteria specified

Correct Answer: A31 The self-referencing constraint limits in a single table the changes to a primary key that the related foreign key defines The foreign key in a self referencing table must specify the DELETE CASCADE rule

Correct Answer: Go to file-aid copy optionEnter the from dataset to be copied and to dataset to which you want to copygo to options Enter 0 at Initial records to skip fieldThen enter 3 at the no of records to skip field and 1 to no of records to selectpress enter and PF3

Correct Answer: Because SALARY is not declared to have NULLs and the employees for whom the salary is not known are also counted

Correct Answer: An application plan or package is generated by the bind to define an access path