Consider a transaction that updates each of the 100 employees' salaries in a table (there is one row per employee)under the immediate update mode.The transaction terminates abnormally after 10 rows have been updated in the database (and the normal operations have taken place on the log).What should the recovery procedure perform to make sure the transaction completes as desired?
A) Redo
B) Redo followed by execution of the transaction again
C) Undo
D) Undo followed by execution of the transaction again

Question

Quizplus · Accepted Answer

Since the transaction was terminated abnormally after updating only 10 rows, we need to perform an undo operation to ensure that the partially updated rows are restored to their previous state. After this, we can execute the transaction again to update the remaining 90 rows. Therefore, the best choice is to perform an undo operation followed by execution of the transaction again.

Consider a Transaction That Updates Each of the 100 Employees