____ means that the data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.a)Consistencyb)Isolationc)Durabilityd)Atomicity

Select one:a.The data item X cannot be accessed by any other transaction T2 until the transaction T1 is completed and the data item X is used by the transaction T1.b.By using the data used during a transaction, the second transaction will not be able to use it until the first has been executed.c. All of the aboved.It enforced the isolation property via its concurrency control subsystem.

Atomicity. A transaction is an atomic unit of processing; it should either beperformed in its entirety or not performed at all.■ Consistency preservation. A transaction should be consistency preserving,meaning that if it is completely executed from beginning to end withoutinterference from other transactions, it should take the database from oneconsistent state to another.■ Isolation. A transaction should appear as though it is being executed in iso-lation from other transactions, even though many transactions are executing7Undo and redo are discussed more fully in Chapter 23.21.4 Characterizing Schedules Based on Recoverability 755concurrently. That is, the execution of a transaction should not be interferedwith by any other transactions executing concurrently.■ Durability or permanency. The changes applied to the database by a com-mitted transaction must persist in the database. These changes must not belost because of any failure.

Discuss Consistency and Isolation property of a transaction

What does the term "degree 3 consistency" ensure in a transaction?Question 24Select one:A.Transaction T does not read dirty data from other transactions.B.Other transactions do not dirty any data read by T before T completes.C.Transaction T does not overwrite dirty data of other transactions.D.Transaction T does not commit any writes until it completes all its writes.E.All the choices apply

What does the isolation property of transactions aim to prevent?Hardware failuresData inconsistenciesConcurrent access issuesDatabase corruptionReview AnswerNext