Thomas write rula andview serializability
Timestamp ordering ensures conflict serializability


proof :

Assume that in precedence graph of schedule, we have edge $T_i \rightarrow T_j$.

Now, When $T_j$ puts it's request for this conflicting operation it will be continue only if $\text{timestamp}(T_i) &lt; \text{timestamp}(T_j)$.

Now, for schedule to be non conflict serializable there must exist a cycle in precedence graph of that schedule and let say that cycle is $T_i, T_{i+1}, ...., T_i$.

Now, note that that cycle can't exist because existence of cycle implies $\text{timestamp}(T_i) &lt; \text{timestamp}(T_i)$. (As timestamp are unique.)

So, we conclude that there can't be any such cycle which in turn implies that timestamp ordering protocol allows only conflict serializable schedules.