View Serializability: 3 Transactions (A bit Tricky ) Doubt Question

[@venkateswararaoinjarapu1636]

This is the best video I came across till now related to view serializability.Great work.

[@ritukapurclasses1591]

+Injarapu Venkateswara Rao thnku :)

[@rohitparmar5944]

One of best video ❤❤❤

[@SomeshCodes]

We check for Initial Read , W->R sequence , Final Write for each data item

[@M_Abdullah_Azeem]

W->R should be avoided?

[@bhojaramsa9353]

Easily understood.. And nice handwriting

[@ritukapurclasses1591]

Thank you...

[@zawette]

thank you for making these in English ! very helpful

[@ritukapurclasses1591]

Thank you...

[@RuneViniGarcia]

Thanks for the video

[@ritukapurclasses1591]

Our pleasure!

[@akankshadewangan4665]

Best mam

[@job_freak]

Your voice is superb

[@ritukapurclasses1591]

Thank you 😊

[@shourabhpayal1198]

shouldn't we just check for w-r conflicts only ? apart from initial read and final update

[@jenavanijenavani2158]

Mam can you solve this question Consider the following schedules. The action are listed in the order they are schedule, and prefixed with transaction name. S1:T1:R(X), T2:R(X), T1:W(Y), T2:W(Y), T1:R(Y), T2:R(Y) S2:T3: R(X), T1:RX), T1: W(Y), T2:R(Z), T2:W(Z), T3:R(Z) For each of the schedules, answer the following questions: (i) What is the precedence graph for the schedules? (ii) Is the schedule conflict-serializable? If so, what are all the conflict equivalent serial schedules? (iii) Is the schedule view -serializable? Id so, what are all the view equivalent serial schedules?

[@ritukapurclasses1591]

Sure, posting solution in 5 mins. Stay tuned and watch related videos in the playlist for precedence graph, conflict pairs, and gate 2020 question on conflict equivalent schedules

[@ritukapurclasses1591]

video posted plz have a look at the solution 😊

[@sayedulabrar2574]

Madam at the time of checking view equivalencies do we need to check for R2(B)->W1(B) between original schedule and new schedule

[@NaitikMishra-ll7el]

nice explanation

[@ritukapurclasses1591]

Thanks and Keep watching😊

[@yasharthgupta9002]

Hi Ma'am, Can we get a different solution of the above problem if we solve it using conflict serializability or the solution of both the methods have to be same?

[@M_Abdullah_Azeem]

Goat!!!

[@ritukapurclasses1591]

Greatest of all time - thank you 😊

[@FilminTamil]

mam at finally it is view serializability or not ?

[@ritukapurclasses1591]

Yes it is as we obtain the serial schedule t2 t1 t3

[@FilminTamil]

@@ritukapurclasses1591 tq mam

[@FilminTamil]

@@ritukapurclasses1591 you only gave the fastest reply mam which not even any channel did tq mam

[@ritukapurclasses1591]

Thanks 😊

[@yashmehta8914]

Please give solution to this problem: R4(A);R2(A);R3(A);R3(B);W2(B).

[@ritukapurclasses1591]

Its very simple... You just need to keep T2 towards the end as rest all transactions are just reading the data items.

[@ritukapurclasses1591]

So, the answer is that it is view serializable and the various serial schedules are: T1:T3:T4:T2 T3:T1:T4:T2 T4:T1:T3:T2 T4:T3:T1:T2 T1:T4:T3:T2 T3:T4:T1:T2

[@piyushgaurav5193]

Please give solution to this problem: R1(A);W1(B);R2(A);W2(B);R3(A);W3(B). Its making me very confusing

[@ritukapurclasses1591]

Hello Piyush. This is a very simple question, which can be easily solved by precedence graph method. Just draw the graph and you will find out the order as T1:T2:T3. This is because T1 node will have in-degree = 0 and out-degree = 2, T2 has in-degree=out-degree=1 and T3 has in-degree=2 and out-degree=0 .

[@piyushgaurav5193]

Thank you for your reply. I need to count number of view serializable schedule possible.

[@ritukapurclasses1591]

Solution: While solving for view serializability, when you consider Item B's case, you get to find that T3 performs final update. Hence, only T3 needs to be at the end in the order. Thus only two orders are possible: T1->T2->T3 and T2->T1->T3.

[@piyushgaurav5193]

R1(A);W1(B);R2(A);R4(A);W2(B);R3(A);W3(B);W4(B). How many view serializable schedule?

[@ritukapurclasses1591]

6 possibilities.

[@sumitgoyal385]

hello di thanks ye to samajh agya tha i posted 2 link is link se gadbadi hai # www.edugrabs.com/questions-on-view-serializable/

[@ritukapurclasses1591]

+sumit goyal The page has many questions in it... Which particular question are you facing the difficulty in?

[@sumitgoyal385]

bas is link me 2 questions starting ke 🙏 🙏 🙏 🙏 🙏 please upload on them

[@ritukapurclasses1591]

+sumit goyal sure :)

[@sumitgoyal385]

thnku

[@bhagyashreepatle1066]

What about w1(B) n w2(B) conflict I think there is conflict Because in new schedule we are updating B by T2 first then T1