• New York Institute of Technology, Manhattan

• CSCI 760

1. What update anomalies occur in the EMP_PROJ and EMP_DEPT relations of Figure 15.3 and 15.4? Provide examples. This study source was downloaded by 100000874968972 from CourseHero.com on 04-13-2024 11:19:23 GMT -05:00 https://www.coursehero.com/file/28829517/hw4-Bhambure-Vdoc/ Ans: In EMP_DEPT, the transitive dependency (Ssn) to (Dnumber) to (Dname and Dmgr_ssn) can cause anomalies. And also with looking at the EMP_PROJ second, the partial dependencies (Ssn) to (Ename) and (Pnumber) to (Pname and Plocation) can cause anomalies. Insertion anomalies: i) To insert a new employee tuple into EMP_DEPT, we must include either the attribute values for the department that the employee works for, or null. ii) It is difficult to insert a new department that has no employees as yet in the EMP_DEPT relation. Deletion anomalies: If we delete from EMP_DEPT an employee tuple that happens to represent the last employee working for a particular department, the information concerning that department is lost from the database. Modification anomalies: In EMP_DEPT, if we change the value of one of the attributes of a particular department, for example manager of department 5 then we must update the tuples of all employees who work in that department, otherwise the database will become inconsistent. 2. Consider the relation REFRIG(MODEL#, YEAR, PRICE, MANUF_PLANT, COLOR), which is abbreviated as REFRIG(M, Y, P, MP, C), and the following set of F of functional dependencies: F={M→ MP, {M,Y} → P, MP→ C} a. Evaluate each of the following as a candidate k