Managing Multiuser Databases The transaction log contains a copy of every database record (or page) after it has changed. These records are called before images. True False True False ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Two transactions that run concurrently and generate results that are consistent with the results that would have occurred if they had run separately are referred to as serializable transactions. True False True False ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases The size of the lock is referred to as the lock granularity. False True False True ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases The lost update problem is when User A reads data that have been processed by a portion of a transaction from User B. True False True False ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases In this instance, dirty reads are disallowed, while nonrepeatable reads and phantom reads are allowed. Read uncommitted Repeatable read Read committed Serializable Read uncommitted Repeatable read Read committed Serializable ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases The advantage of optimistic locking is that: the lock never needs to be obtained. the lock is obtained only after the transaction has processed. transactions that are best suited are those with a lot of activity. the lock is obtained before the transaction has processed. the lock never needs to be obtained. the lock is obtained only after the transaction has processed. transactions that are best suited are those with a lot of activity. the lock is obtained before the transaction has processed. ANSWER DOWNLOAD EXAMIANS APP