The outer-join operations extend the natural-join operation so that tuples from the participating relations are not lost in the result of the join. Describe how the theta join operation can be extended so that tuples from the left, right, or both relations are not lost from the result of a theta join.
Answer to relevant QuestionsConsider the relational database of Figure. Give an expression in the relational algebra for each request:a. Modify the database so that Jones now lives in Newtown.b. Give all employees of First Bank Corporation a 10 percent ...Let the following relation schemas be given: R = (A, B, C) S = (D, E, F) Let relations r(R) and s(S) be given. Give an expression in the tuple relational calculus that is equivalent to each of the following: a. II ...Consider the insurance database of Figure, where the primary keys are underlined. Construct the following SQL queries for this relational database.a. Find the total number of people who owned cars that were involved in ...Consider the SQL query select p.a1 from p, r1, r2 where p.a1 = r1.a1 or p.a1 = r2.a1. Under what conditions does the preceding query select values of p.a1 that are either in r1 or in r2? Examine carefully the cases where one ...Consider the employee database of Figure. Give expressions in QBE, and Datalog for each of the following queries:a. Find the names of all employees who work for First Bank Corporation.b. Find the names and cities of ...
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