Managing Multiuser Databases The size of a lock is called: lock granularity exclusive lock implicit lock shared lock lock granularity exclusive lock implicit lock shared lock ANSWER DOWNLOAD EXAMIANS APP
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 Locks placed by the DBMS are called ________ . shared locks explicit locks implicit locks exclusive locks shared locks explicit locks implicit locks exclusive locks ANSWER DOWNLOAD EXAMIANS APP
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 The advantage of optimistic locking is that: the lock is obtained before the transaction has processed. transactions that are best suited are those with a lot of activity. the lock never needs to be obtained. the lock is obtained only after the transaction has processed. the lock is obtained before the transaction has processed. transactions that are best suited are those with a lot of activity. the lock never needs to be obtained. the lock is obtained only after the transaction has processed. ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Locks placed by command are called ________ . implicit locks exclusive locks shared locks explicit locks implicit locks exclusive locks shared locks explicit locks ANSWER DOWNLOAD EXAMIANS APP