https://gateoverflow.in/118640/gate2017-2-44
Actually, the answer provided in GATE-2017 question, didn't satisfy me.
I did with my approach, you may check it.
@BASANT KUMAR
Don't add two different questions, in one post from next time.
NEW APPROACH :-
For question 1 :-
see my answer at https://gateoverflow.in/118640/gate2017-2-44?show=289691#a289691
For question 2:-
Before coming to question 2, please understand the procedure which is used in the Q1, due to it is same concept
For clarity images :- https://drive.google.com/open?id=1dka-cqVm6ZppPI81Mm9WztqV_pG5iMMh
Recommended to see the same type of question https://gateoverflow.in/272638/total-conflict-serializable-schedules
OLD APPROACH :-
For Question 1 :-
For clarity images https://drive.google.com/open?id=1o12YFKd8JLhlXWLB1D3tuph91ENJ0OCd
For Question 2 :-
For Case 3 and Case 4 :-
Note that R2(B) should be after W1(B)
@shaik masthan i understood the second part T2->T1(53) of first question but i am not getting T1->T2 of first question why there is only one possibility is it because in same schedule they should follow the same order but my doubt is that r(a) w(a) and r(b)w(b) is there one on data item a and other on b so cant they permute beacuse they are on reading and writing on different data item so how it will make difference in answer
why cant they should be like these R(B)W(B)R(A)W(A)R(C)W(C)R(B)W(B)
then we can get more possiblity
please tell me where i am going wrong
why there is only one possibility is it because in same schedule they should follow the same order
yes, with in a transaction you have to follow the order ===> after completing the operation R(B) it should go to W(B) then R(C) after that only W(C)
@Shaik Masthan
Can you please explain the solution to the 2nd question a bit?
I am not getting the cases..The way I solved is giving me more no. of schedules..
why you only take Write - Read conflict here
By draw topological diag it's very easy to solve but I didn't understand that how you made it
acc to question 2
This topology is correct ???
but acc to this topology "correct answer is not coming :/ "
that is DAG, So excess links removed !
if you didn't get it, just assume, 3 --> 6 you drawn a link.
Then think 6 should be after 3 and 4, and 4 should be after 3 ==> you must have to do 3--> 4--->6
Your DAG, representating T1 --> T2
In the first method, second image –
https://drive.google.com/file/d/1Z-tlThOEyVlBjV8Zky5_Wc3z7L-hvSGc/view?usp=sharing
Total number of possibilities such that T2->T1 = T1->T2 = 56 is because of the symmetricity of the DAG, right? i.e if we draw the graph for T2->T1 it will be same as that of T1->T2 with the corresponding labels interchanged(G for A, H for B etc) , right?
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