Question

Consider the following statements about schedules in database:

$S_1:\text{Dirty read problem is same as write-read conflict.}$
$S_2:\text{Unrepeatable reads is also known as read-write conflict}$

$S_3:\text{Strict two phase locking may have read-write conflict.}$

Which of the above statements are correct?

• A. $Only{S}_{1}and{S}_2$
• B. $All{S}_1,S_{2}and{S}_1$
• C. $Only{S}_{1}and{S}_3$
• D. $Only{S}_{2}and{S}_3$

Answer 1

The correct option is A $Only{S}_{1}and{S}_2$

$S_1:$
Dirty read problem is same as write-read conflict in which a transaction is reading a data from a uncommitted transaction
$S_{1}iscorrect.$

$S_2:$
Unrepeatable reads is also known as read-write conflict
$S_{2}iscorrect$

$S_3:$
Strict 2PL can not have read-write conflict,
$S_{3}isincorrect$

So option (a) is true.