Transactions TESTBOOK Question

Question

A) View serializable but not conflict

b) both

c) neither

d) Conflict but not view

Comments

@ Prajwal How are you getting T2->T1->T3

---

Check my ans!

---

Yes you are correct my approach in recognising blind write is checking if there is a read before write or not here in T1 and T3 is is not present so there is blind write hence view serializability but your approach is different

Answer 1

First check for Conflict serializable 

T2->T1    R-W and T1->T2 W-W conflict ,Hence not Conflict serializable 

A Schedule which is not conflict serializable to be View serializable should have Blind Write, here blind writes are there 

For View serializability

First Read n Last write  should be performed by same transaction as original transaction and writer-reader order should be satisfied

Here here is no write-read problem ,Hence T2-> T1 ->T3 satisfies it 

Comments

Can u pls share some reference to view rules .?

---

Watch these 2 videos:

https://www.youtube.com/watch?v=IYaxn0qkzUI&list=PLJlNUj7NeX8gguRftmy3-zqEhYrM_r8S0&index=24

https://www.youtube.com/watch?v=NWmhKcjAoNI&index=21&list=PLbKVlnc3OmnwG-2-EeoheUZxBHwJhRaZ-

Answer 2

I Think it is VS but not CS....

Comments

I am getting answer C but answer is a please anybody can explain

---

To check for VS just make the polygraph and see if there is a cycle if not then it is VS

---

what is poly graph ? can u pls exapin ?

---

http://www.edugrabs.com/how-to-check-for-view-serializable-schedule/ check this