Case in Point 9.2 CyberToys You handle administrative support for CyberToys, a s
ID: 3600475 • Letter: C
Question
Case in Point 9.2 CyberToys
You handle administrative support for CyberToys, a small chain that sells computer hardware and software and specializes in personal service.The company has four stores located at malls and is planning more. Each store has a manager, a technician, and between one and four sales reps.
Bruce and Marcia Berns, the owners, want to create a personnel records database, and they asked you to review a table that Marcia designed. She suggested fields for store number, location, store telephone, manager name, and manager home telephone. She also wants fields for technician name and technician home telephone and fields for up to four sales rep names and sales rep home telephones.
Draw Marcia's suggested design and analyze it using the normalization concepts you learned in the chapter.What do you think of Marcia's design and why? What would you propose?
Explanation / Answer
I SUGGEST THAT IT IS BETTER IF MARCIA ASSIGNS UNIQUE ID FOR EACH EMPLOYEE,i.e to sales_representative
we get redundancies and anomolies if we palce all the entries in one table..normalization was proposed inorder to eliminate these suituations.Normalization means dividing the table into smaller.
why i proposed unique id is with same name two sales persons working in same store may have same name
tables are
store(store_no,location,store_phone,manager_name,manager_phone,technician_name,technician_phone,sales_rep,
sales_rep_num)
this is large table and has redundancies so we have to eliminate them
1.store(store_no,location,manager_name,techinican name)
2.phone(store_no,field,phone_no)
3.sales_rep(store_no,sales_rep_name,phone_no)
using these attributes we can design this one only though it contains redudancy..
if we use another attribute of unique id we will the reduce the redundancies more
like
employee(id,name)
store(store_no,location,manager_id,technician_id)
sales(store_no,id);
phone(id,phone_no);