Question: Show that with n relations there are 2 n 1 n 8
Show that, with n relations, there are (2(n − 1))! / (n−1)! Different join orders. If you wish, you can derive the formula for the number of complete binary trees with n nodes from the formula for the number of binary trees with n nodes. The number of binary trees with n nodes is 1/n+1 (2n n); this number is known as the Catalan number, and its derivation can be found in any standard textbook on data structures or algorithms.
Answer to relevant QuestionsShow that the lowest-cost join order can be computed in time O(3n). Assume that you can store and look up information about a set of relations (such as the optimal join order for the set, and the cost of that join order) in ...Give an example of an expression defining a materialized view and two situations (sets of statistics for the input relations and the differentials) such that incremental view maintenance is better than recomputation in one ...Explain the distinction between the terms serial schedule and serializable schedule.What benefit does rigorous two-phase locking provide? How does it compare with other forms of two-phase locking?In timestamp ordering, W-timestamp (Q) denotes the largest timestamp of any transaction that executed write (Q) successfully. Suppose that, instead, we defined it to be the timestamp of the most recent transaction to execute ...
Post your question