3. Deadlocks happen when two or more access operations happen at the same time in a database. In an HR operation, the HR Clerk is trying to add a new employee records which were recommended by the Director, while the Senior HR Officer is trying to use salaries to calculate this month's pay out. A third operation on the salaries involves the HR Manager who wants to know who was employed last month so that their salaries reflect in this month's payroll. Write out a scenario with schematics (or diagrams) to show a typical deadlock situation that would arise as a result of the scenario given. a. b. What granularity would you recommend to use for each of these operations, and why? c. What would a scheduler's role be in this scenario? Which would be best according to your understanding of deadlock resolution? d. Recommend a suitable, future solution based on: i. Optimistic Approach. ii. Pessimistic Approach. Human Resources (HR) Schema DEPARTMENT ID DEPARTMENT_NAME MANAGER_ID LOCATION ID EMPLOYEE_ID START DATE END_DATE JOB_ID DEPARTMENT_ID LOCATION ID STREET_ADDRESS POSTAL CODE CITY STATE_PROVINCE COUNTRY_ID has in LOCATIONS DEPARTMENTS JOB HISTORY Works_in Managed by was in has COUNTRY_ID COUNTRY NAME REGION ID COUNTRIES EMPLOYEES has JOBS JOB_ID JOB_TITLE MIN SALARY MAX_SALARY in Manager JOB_GRADES REGIONS EMPLOYEE_ID FIRST_NAME LAST_NAME EMAIL PHONE NUMBER HIRE_DATE JOB ID SALARY COMMISSION_PCT MANAGER ID DEPARTMENT_ID GRADE_LEVEL LOWEST_SAL HIGHEST_SAL REGION_ID REGION_NAME 3. Deadlocks happen when two or more access operations happen at the same time in a database. In an HR operation, the HR Clerk is trying to add a new employee records which were recommended by the Director, while the Senior HR Officer is trying to use salaries to calculate this month's pay out. A third operation on the salaries involves the HR Manager who wants to know who was employed last month so that their salaries reflect in this month's payroll. Write out a scenario with schematics (or diagrams) to show a typical deadlock situation that would arise as a result of the scenario given. a. b. What granularity would you recommend to use for each of these operations, and why? c. What would a scheduler's role be in this scenario? Which would be best according to your understanding of deadlock resolution? d. Recommend a suitable, future solution based on: i. Optimistic Approach. ii. Pessimistic Approach. Human Resources (HR) Schema DEPARTMENT ID DEPARTMENT_NAME MANAGER_ID LOCATION ID EMPLOYEE_ID START DATE END_DATE JOB_ID DEPARTMENT_ID LOCATION ID STREET_ADDRESS POSTAL CODE CITY STATE_PROVINCE COUNTRY_ID has in LOCATIONS DEPARTMENTS JOB HISTORY Works_in Managed by was in has COUNTRY_ID COUNTRY NAME REGION ID COUNTRIES EMPLOYEES has JOBS JOB_ID JOB_TITLE MIN SALARY MAX_SALARY in Manager JOB_GRADES REGIONS EMPLOYEE_ID FIRST_NAME LAST_NAME EMAIL PHONE NUMBER HIRE_DATE JOB ID SALARY COMMISSION_PCT MANAGER ID DEPARTMENT_ID GRADE_LEVEL LOWEST_SAL HIGHEST_SAL REGION_ID REGION_NAME