A phantom read problem may occur when a transaction changes the value of an object that has been read by another transaction several times.Question 4Select one:TrueFalse

A dirty read occurs when a transaction reads data that has been modified by another transaction but not yet committed.Question 14AnswerTrueFalse

A lost update problem may occur between two transactions when these two transactions have read-write conflicts.Question 2Select one:TrueFalse

What type of consistency level prevents all three phenomena: dirty read, non-repeatable read, and phantom read?Question 5Select one:A.Read CommittedB.Repeatable ReadC.Read UncommittedD.SerializableE.Snapshot Isolation

Which technique is commonly used in database systems to handle "phantom reads"?Using shared locks for all read operations.Applying range locks to cover the search criteria.Escalating row-level locks to table-level locks.Implementing timestamp-based version control

Which of the following scenarios may lead to an irrecoverable error in a database system?A transaction reads a data item after it is written by a committed transactionA transaction writes a data item after it is read by an uncommitted transactionA transaction reads a data item after it is written by an uncommitted transactionA transaction reads a data item after it is read by an uncommitted transaction