Consider the following normalized relations for a database in a large retail store chain:
EMPLOYEE(Emp_Id, Work_Location, Name, Address)
STORE(Store_ID, Region, Manager_ID, Square_Feet)
DEPARTMENT(Dep_ID, Manager_ID, Sales, Goal)
SCHEDULE(Dep_ID, Emp_ID, Date)
Assume that a data communications network links a computer at corporate headquarters with a computer in each retail outlet. The chain includes 50 stores with an average of 75 employees per store. There are 10 departments in each store. A daily schedule is maintained for 5 months (the previous 2 months, the current month, and next 2 months). Further assume that:
- Each store manager updates the employee work schedule for her or his store roughly five times per hour.
- The corporation generates all payroll checks, employee notices, and other mailings for all employees for all stores.
- The corporation establishes a new sales goal each month for each department.
- The corporation hires and fires store managers and control all information about store managers; store managers hire and fire all store employees and control all information about employees in that store.
a. Would you recommend a distributed database, a centralized database, or a set of decentralized databases for this retail store chain? Justify your answer.
b. Assuming that some form of distributed database is justified, what would you recommend as a data distribution strategy for this retail store chain? Justify your answer.