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 Which of the following occurs when one transaction reads a changed record that has not been committed to the database? Dirty read Consistent read Phantom read Nonrepeatable read Dirty read Consistent read Phantom read Nonrepeatable read ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases In this instance, dirty reads are disallowed, while nonrepeatable reads and phantom reads are allowed. Repeatable read Read committed Read uncommitted Serializable Repeatable read Read committed Read uncommitted Serializable 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 Locks placed by the DBMS are called ________ . explicit locks shared locks exclusive locks implicit locks explicit locks shared locks exclusive locks implicit 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