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. the lock is obtained only after the transaction has processed. transactions that are best suited are those with a lot of activity. the lock is obtained before the transaction has processed. the lock never needs to be obtained. the lock is obtained only after the transaction has processed. transactions that are best suited are those with a lot of activity. ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Locks placed by the DBMS are called ________ . explicit locks shared locks implicit locks exclusive locks explicit locks shared locks implicit locks exclusive locks 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 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? Consistent read Phantom read Nonrepeatable read Dirty read Consistent read Phantom read Nonrepeatable read Dirty read ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases Two transactions that run concurrently and generate results that are consistent with the results that would have occurred if they had run separately are referred to as serializable transactions. False True False True ANSWER DOWNLOAD EXAMIANS APP
Managing Multiuser Databases What is the overall responsibility of the DBA? Development, operation, and maintenance of the database and its applications Facilitate the development and use of the database Create and populate tables Both the first and third answers above are correct. Development, operation, and maintenance of the database and its applications Facilitate the development and use of the database Create and populate tables Both the first and third answers above are correct. ANSWER DOWNLOAD EXAMIANS APP
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