3 votes 3 votes T1 T2 W(x) R(x) W(x) ABORT COMMIT Databases view-serializable serializability databases normal + – sumit goyal 1 asked Dec 25, 2017 edited Jul 17, 2019 by Satbir sumit goyal 1 3.7k views answer comment Share Follow See all 17 Comments See all 17 17 Comments reply Show 14 previous comments Kiran Karwa commented Dec 27, 2017 reply Follow Share @nitish Here T2 is reading a old value written by T1. When we do T1->T2 here now T2 would be reading the final updated value by T1. But as per my knowledge RAW have to be maintained in the view serialised schedule, Isn't it? Am I missing out something? 0 votes 0 votes Rupendra Choudhary commented Dec 27, 2017 reply Follow Share Hello sumit i just came to realize last night that i wrote something wrong there which i'm correcting now.Pardon me that i delivered you wrong knowledge. All three conditions are iff (bidirectional) conditions. But in hasten i misinterpreted meaning of 'iff'. iff is like either A and B both will happen or neither will happen $\overline{A} . \overline{B} + A.B$ So conditions are like let suppose in Schedule $S$ transaction $T_{1}$ performed initial read on data item $'A'$ then in view serializable schedule also A have to perform initial read on $'A'$ , let suppose there $T_{1}$ didn't perform initial read then in view serializable schedule also $T_{1}$ can't perform initial read on $'A'$ others conditions are also in same manner. 2 votes 2 votes sumit goyal 1 commented Dec 27, 2017 reply Follow Share thnks bro 0 votes 0 votes Please log in or register to add a comment.
13 votes 13 votes T2 is aborted. In all such cases consider that we have only one transaction. So it is Conflict Serializable and View Serializable. Ahwan answered Dec 26, 2017 Ahwan comment Share Follow See 1 comment See all 1 1 comment reply dheerwani commented Aug 8, 2018 reply Follow Share Yus that's the correct answer 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes Here T2 is aborted so we can say that there is some failure occur due to which it is recovering so now we can say that we are having only one transaction T1 so it is both conflict serializable as well as view serializable Prince Sindhiya answered Sep 8, 2018 Prince Sindhiya comment Share Follow See 1 comment See all 1 1 comment reply Shivateja MST commented Nov 8, 2019 reply Follow Share Does it mean that the conflicts which actually seems to occur are temporary since T2 is aborted? 0 votes 0 votes Please log in or register to add a comment.