Managing Multiuser Databases The advantage of optimistic locking is that: transactions that are best suited are those with a lot of activity. the lock is obtained before the transaction has processed. the lock is obtained only after the transaction has processed. the lock never needs to be obtained. transactions that are best suited are those with a lot of activity. the lock is obtained before the transaction has processed. the lock is obtained only after the transaction has processed. the lock never needs to be obtained. ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases A transaction for which all committed changes are permanent is called: isolated. durable. consistent. atomic. isolated. durable. consistent. atomic. ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Which of the following occurs when a transaction rereads data it has previously read and finds modification or deletions caused by a committed transaction? Nonrepeatable read Dirty read Phantom read Consistent read Nonrepeatable read Dirty read Phantom read Consistent read ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases An exclusive lock locks the item from change but not from read. True False True False ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Locks placed by command are called ________ . exclusive locks implicit locks shared locks explicit locks exclusive locks implicit locks shared locks explicit locks 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
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