Strict schedules (SS)

[Almersy Shing]

Hi,

For the last page of trans_inew, there is an example of SS:  Example: T1.R(X), T2.R (X), T1.W(X), COMMIT.T1, T2.W(X), COMMIT.T2.

I got confused why it is SS?

According to the defination of SS:  A value written by a transaction is not read or overwritten by other transactions until T either aborts or commits.

When considering about T1.W(X), the value of X is read by T2 (we have T2.R(X) before T1.W(X)) before T2 is commit. So I thought it is not SS. Where did I get wrong?

Thanks.

[Yu Hao]

Hi Almersy,

In the definition, A value written by a transaction is not read or overwritten by other transactions until T either aborts or commits.

For the example, T1.R(X), T2.R (X), T1.W(X), COMMIT.T1, T2.W(X), COMMIT.T2.

The first two are Read instead of Write.

The first W() is T1.W(X), which is committed before being overwritten.

Therefore, it is a SS,

Cheers,

Yu

[Almersy Shing]

Thanks, Yu!