18.3 Test Questions By Donavon M. Norwood 03/04/2009
Locks are use on database elements to: Maintain the locking table Request from transactions Prevent unauthorized access to DB Prevent unserializable behavior
2) The scheduler uses the Locking Table to: Backup the database Join two tables Issue select statements from users None of the above
3) Locks have the intended meaning: Locks DB from unauthorized access Allows access to Locking table No two transactions may have locked the same element without one having first released the lock Allows transactions to be consistent/inconsistent
4) The Locking Table is used by the scheduler to: Process data Provide a illegal schedule of transactions Commit data written by transactions Guide the decision of the scheduler to allow or block transactions
5) Which is the correct events for locking: a) r(A); u(A); w(A); l(A) b) w(A); u(A); r(A); l(A) c) l(A); r(A); w(A); u(A) d) u(A); w(A); l(A); r(A);
GOOD LUCK!