Why is it not desirable to force users to make an explicit choice of a queryprocessing strategy? Are there cases in which it is desirable for users to be aware of the costs of competing query-processing strategies? Explain your answer.
Answer to relevant QuestionsConsider the following SQL query for our bank database select T.branch-name from branch T, branch S where T.assets > S.assets and S.branch-city = “Brooklyn” Write an efficient relational-algebra expression that is ...The indexed nested-loop join algorithm described in Section 13.5.3 can be inefficient if the index is a secondary index, and there are multiple tuples with the same value for the join attributes. Why is it inefficient? ...Clustering indices may allow faster access to data than a nonclustering index affords. When must we create a nonclustering index, despite the advantages of a clustering index? Explain your answer.SQL allows relations with duplicates. a. Define versions of the basic relational-algebra operations σ, Π, ×, Π, −, ∪, and ∩ that work on relationswith duplicates, in a way consistent with ...Suppose that there is a database system that never fails. Is a recovery manager required for this system?
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