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1. (10 Points) Given two relations R1 and R2, where R1 contains N1 tuples, R2 contains N2 tuples, and N2 > N1 > 0, give the minimum and maximum possible sizes (in tuples) for the resulting relatio... n produced by each of the following relational algebra expressions. In each case, state any assumptions about the schemas for R1 and R2 needed to make the expression meaningful: Expression Assumption Minimum Maximum R1 ∪ R2 R1 and R2 are domain compatible N2 N1 + N2 R1 ∩ R2 R1 and R2 are domain compatible 0 N1 R1 − R2 R1 and R2 are domain compatible 0 N1 R1 × R2 N1 * N2 N1 * N2 σa=5(R1) R1 has an attribute named a 0 N1 πa(R1) R1 has attribute a, N1>0 1 N1 R1/R2 The set of attributes of R2 is a subset of the set of attributes of R1 0 N1/N2 R2/R1 The set of attributes of R1 is a subset of the set of attributes of R2 0 N2 / N1 2. (10 Points) List the last names of department managers who have no dependents. Use the company database schema on page 2. [Show More]

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