Give an example of a schedule produced by a recoverable but nonstrict concurrency control involving three transactions in which a deadlock occurs, causing a cascaded abort of all three.

What will be an ideal response?

w1(x) r2(x) w2(y) w2(x) w3(z ) r3(y) w3(y) w1(z ) abort1
Transaction 2 is waiting for transaction 1 (because of x); 3 is waiting for 2 (because
of y), and 1 is waiting for 3 (because of z ). So 1 is aborted (because for example, 1
wrote x and 2 requested to write x). But, 2 has read what 1 wrote and hence must be
aborted when 1 is aborted. Transaction 3 has read what 2 wrote and hence must be
aborted when 2 is aborted.