Question 16 :
The goal of database security is to ensure that only authorized users can perform authorized activities at authorized times.
Question 17 :
A phantom read occurs when a transaction rereads data it has previously read and finds modifications or deletions caused by a committed transaction.
Question 18 :
A transaction is a series of actions to be taken on the database so that either all of them are performed successfully or none of them are performed at all.
Question 19 :
A point of synchronization between the database and the transaction log is generally referred to as a stop point.
Question 20 :
An exclusive lock locks the item from change but not from read.