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.
You might also like to view...
Car sharing services like Zipcar are examples of ownership.
Answer the following statement true (T) or false (F)
The Word Web App does not have the ability to edit objects such as SmartArt and WordArt
Indicate whether the statement is true or false
The JList GUI component generates events that call the actionStateChanged method.
Answer the following statement true (T) or false (F)
Public clouds are ________.
A. accessed through an extranet B. accessed through an intranet C. accessed through the internet D. stretched across different businesses in an industry