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? Dirty read Consistent read Phantom read Nonrepeatable read Dirty read Consistent read Phantom read Nonrepeatable read ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Which of the following occurs when a transaction rereads data and finds new rows that were inserted by a command transaction since the prior read? Nonrepeatable read Phantom read Consistent read Dirty read Nonrepeatable read Phantom read Consistent read Dirty read 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 An exclusive lock locks the item from change but not from read. True False True False ANSWER DOWNLOAD EXAMIANS APP
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 only after the transaction has processed. the lock never needs to be obtained. the lock is obtained before the transaction has processed. transactions that are best suited are those with a lot of activity. the lock is obtained only after the transaction has processed. the lock never needs to be obtained. the lock is obtained before 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. True False True False ANSWER DOWNLOAD EXAMIANS APP