How to check the view serializability of a given schedule ?

Question

Suppose we have a schedule containing two transactions  as shown-

$\begin{bmatrix} T1 & T2 \\ R(A) & \\ W(A) & \\ & R(A) \\  & W(A) \\ R(B)& \\ W(B)& \\ & R(B) \\  & W(B) \end{bmatrix}$

 

We will proceed to create the polygraph for the above schedule..my doubt is that do we need to create the polygraph for both the items A, B or just a single polygraph for the entire schedule. If we create separate polygraphs, for A we will get t1->t2, and for B we will get t1->t2.. Same graph will be obtained if we draw a single polygraph

Answer 1

you should draw a single graph.else you will not succeed to figure out the cycle,alltime,which is an important thing for deciding conflict or non conflict serialization

Comments

Can we get conflict equivalent serial order and view equal serial order from the same polygraph?

I mean do we need to draw both graphs for them separately?

Answer 2

we have to  include them in same polygrah

from that ques u may get it correct but it is not correct approach

Answer 3

The given schedule is view serializable as well as conflict serializable.

As its is conflict serializable and not having any blind writes..it is of course view serializable in nature.