Thomas write rule will guarantee VIEW Serializability as
Suppose you have a schedule S: r1(a) w2(a) w1(a)
suppose you have a Serial Schedule T1T2 i.e. T1 occurs first in the system
T1T2: r1(a) w1(a) w2(a)
We know that T1T2 is a serial schedule as It preserves its first read as in S so we can clearly see that it is not preserving view Serializability as last write should be of T1 but in this serial schedule it is of T1.
Now Thomas write rule comes into picture. as T1 timestamp is less than T2 T1 must have happened before T2. Now its write will be ignored by the system so the schedule now becomes:
S: r1(a) w2(a) w1(a)
And our serial schedule as per Thomas write rule will only be T1 T2 (not T2T1)
T1T2: r1(a) w1(a) w2(a)
Just focus on the strike through
Who is making first read and last write to the data items in both the Serial schedule T1T2 and in our schedule S?
Ans: T1 and T2 respectively
So yes Thomas write rule maintains VIEW SERIALIZABILITY but does not guarantee Conflict Serializability.
Although this explanation will come handy to you in order to solve GATE 2019 question on view and conflict serialisability.