Design a variant of the hybrid merge–join algorithm for the case where both relations are not physically sorted, but both have a sorted secondary index on the join attributes.
Answer to relevant QuestionsThe 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? ...Write pseudocode for an iterator that implements indexed nested-loop join, where the outer relation is pipelined. Use the standard iterator functions in your pseudocode. Show what state information the iterator must maintain ...Show that the following equivalences hold. Explain how you can apply then to improve the efficiency of certain queries: a. E1 Θθ (E2 − E3) = (E1 Θθ E2 − E1 Θθ E3). b. σθ ...Decorrelation:a. Write a nested query on the relation account to find for each branch with name starting with “B”, all accounts with the maximum balance at the branch.b. Rewrite the preceding query, without using a ...Explain the distinction between the terms serial schedule and serializable schedule.
Post your question