Concurrency Strict Schedule

Question

Consider the following database schedule with two transactions T1T1 and T2T2.

S=r2(X);r1(X);r2(Y);w1(X);r1(Y);a1;a2 where a1 and a2 stands for abort.  Is It a strict schedule?

Please explain why or why not?

Comments

Since both transaction going to be abort at last then thier is no problem of lost update and irrecoverability . so yes it is strict recoverable.

Answer 1

A schedule is strict if : A value written by a transaction T is not read or overwritten by other transactions until T either commits or aborts.. so in given schedule W1 (X) is not read or written by other transactions... so it seems to be a strict schedule..

Answer 2

It is not a strict schedule because a schedule is strict if a value written by a transaction cannot be read or over writtten by other transaction until the transaction either commits (or) aborts