1 findthenamesofallemployeeswhoworkforverizonwireless

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Unformatted text preview: id, 2 → pid, 3 → cost)( sR3.cost<R2.cost(R3 × R2)) p pid (R2− p pid,costR4) Exercise 3 (Relational Calculi) [20pts] Consider the following database schema: EMPLOYEE (emp_name, address_street, address_city, phone_no) DEPARTMENT (dept_name, mgr_name, mgr_start_date) WORKS_ON (emp_name, industry_name, salary) INDUSTRY (industry_name, location_city) MANAGES (emp_name, mgr_name) Write both the Tuple Relational Calculus expression and Domain Relational Calculus for the following queries. 1. Find the names of all employees who work for ‘Verizon Wireless’ TRC: {t | s WORKS_ON(t[emp_name] s[emp_name] s[industry_name] ' Verizon Wireless' )} DRC: { p | c, s( p, c, s WORKS_ON c ' Verizon Wi reless' )} 2. Find the names, street address, cities, and phone number of residence of all employees who work for Intel and earn more than $80,000.00 per year TRC: {t | t EMPLOYEE ( s WORKS_ON(s[emp_name] t[emp_name] s[industry_name] ' Intel' s[salary] 80000))} DRC: { p, s, ind | p, ind, s EMPLOYEE indu, sal ( p, indu, sal WORKS_ON indu ' Intel' sal 80000))} 3. Find the names of all employees who live in the same city and on the same street as their managers {t | p EMPLOYEE, q MANAGES, r EMPLOYEE (p[emp_name] q[emp_name] q[mgr_name] r[emp_name] TRC: p[address_street]...
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This note was uploaded on 01/27/2014 for the course COP 5725 taught by Professor Staff during the Spring '08 term at University of Florida.

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