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Consider the relations: PROJECT(proj#,proj_name,chief_architect) EMPLOYEE(emp#,emp_name) ASSIGNED(proj#,emp#) Use relational algebra to express the subsequent queries:(i) Get details of employees working on project COMP33.(ii) Get the employee number of employees who work on all projects.(iii) Get details of project on which employee with name ‘RAM' is working.
Ans:(i) EMPLOYEE ∏Emp#(σproject#='comp33'(ASSIGNED)) (ii) ∏Emp#(EMPLOYEE)-(ASSIGNED ÷∏project#(PROJECT)) (iii) PROJECT (∏project#(σEmp_name='RAM'(EMPLOYEE) ASSIGNED))
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A Relation Schema represented by R(A1, A2, ..., An) is made up of the relation name the list of attributes and R Ai that it contains. A relation is described as a set of tuples
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WHAT IS DATABASE TECHNOLOGIES
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