Managing Multiuser Databases A phantom read occurs when a transaction rereads data it has previously read and finds modifications or deletions caused by a committed transaction. True False True False ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases The advantage of optimistic locking is that: the lock is obtained before 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 only after the transaction has processed. the lock is obtained before 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 only after the transaction has processed. ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases When one transaction reads a changed record that has not been committed to the database a filthy read occurs. False True False True ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases The size of a lock is referred to as lock sizing. True False True False ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases The goal of database security is to ensure that only authorized users can perform authorized activities at authorized times. False True False True ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Locks placed by the DBMS are called ________ . exclusive locks implicit locks shared locks explicit locks exclusive locks implicit locks shared locks explicit locks ANSWER DOWNLOAD EXAMIANS APP