Deadlock Handling in database management system free notes
The simplest scheme under the first approach requires that each transaction locks all its data items before it begins execution. Moreover, either all are locked in one step or none are locked. There are two main disadvantages to this protocol:- (1) it is often hard to predict, before the transaction begins, what data items need to be locked;
(2) data-item utilization may be very low, since many of the data items may be locked but unused for a long time.