Suppose we view it as impossible to have two employees with exactlythe same first names, last names, and birth dates. We have no naturalidentifier for employees.Consider two cases:• Suppose that (firstName, lastName, birthdate) is the composite pri-mary key.• Suppose that a surrogate key is chosen for employees.For each case, show what happens to the employee table if we implementthe 1:M "supervises" relationship between two employees using foreignkeys. Show an example (for each case) of an employee table containing aboss and her two subordinates.(2)Continuing with the surrogate key approach in the previous table, showhow to introduce another entity (or table) to maintain history of the "su-pervises" relationship. (Do something similar to Figure 5.10 or 5.11.) FIGURE 5.10 MAINTAINING MANAGER HISTORYCurrent DataEMPLOYEEDEPARTMENTPKEMP NUMPKDEPT IDEMP LNAMEHE-managesEMP FNAMEEMP INITIALEMP E_MAILJOB_CODEEMP SALARYDEPT NAMEFK1 EMP NUMDATE ASSIGNEMP MGR_HIST%3EMP SAL HISTORYHistoric DataMGR HISTDEPT MGR_HISTSALARY HISTPK,FK1PK,FK2 DEPT IDPKEMP NUMPK,FK1 EMP NUMPKDATE ASSIGNSALARY START DATESALARY_AMTFIGURE 5.11 MAINTAINING JOB HISTORYEMPLOYEECurrent DataPKEMP NUMDEPARTMENTEMP LNAMEEMP FNAMEEMP_INITIAL HE--EMP E MAILFK1 DEPT IDJOB CODEDATE_ASSIGNEMP SALARYPKDEPT IDmanagesDEPT NAMEemploysH-FK1 EMP_NUMDATE ASSIGNHistoric DataJOB HISTDEPT JOB_HISTEMP_JOB HISTPK,FK1 EMP NUMPK,FK2 DEPT IDPKDATE ASSIGN POJOB_CODEEMP SALARY

Answered: Image /qna-images/answer/ca3cdbbf-3ddc-40bd-9280-1c575a61ac55.jpg

Answered: ntifier for employees. nsider two…

ntifier for employees. nsider two cases: • Suppose that (firstName, last Nam mary key. • Suppose that a surrogate kev is ch

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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