Query Processing , Optimizatio

Query Processing , Optimization and Transaction

a) please describe the implementation process of selection operation , where is a relation . is an attribute and is not a candidate key , r has a primary index on . If there are matching records , the + tree index is of height , and each disk block contains at most records , please analyze the overhead in the best case .

b) Describe the process of Indexed nested-loop join .

c) please describe the two-phase looking protocol and prove that it ensures conflict-serializable schedules and does not ensure freedom from deadlocks .