Question

Consider the following schedule that performs actions taken by transactions 71 and T2 on database objects A and B: T1: R(A), WA), RIC), W(B), Commit R(B), W(B), Commit The above schedule results in an) T2: OA cascading aborts OB write-read conflict write-write conflict OD read-write Conflict

Answer 1

Correct Answer:

Explanation:

The given schedule is:

T2 T1 R(A) WCA) R(C) R(B) W(B) Commit W(B) Commit

A schedule is known as a cascade-less schedule in which there is no dirty read. If the dirty read is present then the schedule is not cascade-less.

If a transaction reads data written by uncommitted transaction then this read operation is known as dirty read.

Cascading abort means the failure of one transaction leads to the rollback of the series of transactions.

If a schedule is cascade-less if it avoids cascading abort.

This schedule is cascade-less because there is no dirty bit.

Option A is incorrect because this schedule doesn't result in cascading aborts.

Option B is incorrect because there is no write-read conflict.

Option C is correct because this schedule results in a write-write conflict.

Option D is incorrect because there is no read-write conflict.

So, option C is correct.