Answer: (C)
In strict 2PL, a transaction T does not release any of its exclusive (write) locks until after it commits or aborts.
Hence, no other transaction can read or write an item that is written by T unless T has committed, leading to a strict schedule for recoverability.
-> (Ref: Fundamentals of Database Systems by Elmasri and Navathe, 7e Pg. No. 789)
By ignoring the OUTDATED write, Thomas write rule allows schedules that are not conflict serializable but are nevertheless correct.
Those non-conflict-serializable schedules allowed satisfy the definition of view serializable schedules.
-> (Ref: Database System Concepts by Silberschatch, Korth and Sudarshan, 6e Pg No. 686)
PROOF OF STATEMENT 2 :
Eg:
T1 T2 T3
r(a)
w(a)
r(a)
w(a)
w(a)
This Schedule Is View Serializable but not Conflict Serializable . CHECK IT.
It Is View Serializable To T1T2T3, with T2 having a Blind Write.
NOW SOLVING BY THOMAS WRITE RULE:
-> By TimeStamp Ordering , Correct Order Is : T1T2T3.
-> But CONFLICT w2(a)r1(a) is not in Timestamp order.
-> But Thomas write rule can ignore it as this is Outdated Write. So w1(a) can be completely IGNORED from The Transaction .
-> Other Remaining Conflicts (with w1(a) discarded) are r1(a)w3(a), w2(a)r3(a),w2(a)w3(a) which are in Correct Timestamp Order.
-> Thus after ignoring 1 OUTDATED WRITE , THOMAS WRITE RULE ACCEPTED A SCHEDULE WHICH IS VIEW SERIALIZABLE AND NOT CONFLICT SERIALIZABLE.