Posted: March 9th, 2021
1. Assume that at Pine Valley Furniture products are composed of components, products are assigned to salespersons, and components are produced by vendors. Also assume that in the relation PRODUCT (Prodname, Salesperson, Compname, Vendor), Vendor is functionally dependent on Compname and Compname is functionally dependent on Prodname. Eliminate the transitive dependency in this relation and form 3NF (third normal form) relations.
2. Transform the E-R diagram of Figure 8-3 into a set of 3NF relations. Make up a primary key and one or more non-keys for each entity.
3. Transform the E-R diagram of Figure 9-21 into a set of 3NF relations.
4. Consider the list of individual 3NF relations below. These relations were developed from several separate normalization activities.
PATIENT(Patient_ID, Room_Number, Admit_Date, Address)
ROOM(Room_Number, Phone, Daily_Rate)
PATIENT(Patient_Number, Treatment_Description, Address)
TREATMENT(Treatment_ID, Description, Cost)
PHYSICIAN(Physician_ID, Name, Department)
PHYSICIAN(Physician_ID, Name, Supervisor_ID)
(a) Merge these relations into a consolidated set of 3NF relations. State whatever assumptions you consider necessary to resolve any potential problems you identify in the merging process. (b) Draw an E-R diagram for your answer to part “a”.
5. Consider the following 3NF relations about a sorority or fraternity:
MEMBER(Member_ID, Name, Address, Dues_Owed)
OFFICE(Office_Name, Officer_ID, Term_Start_Date, Budget)
EXPENSE(Ledger_Number, Office_Name, Expense_Date, Amt_Owed)
PAYMENT(Check_Number, Expense_Ledger_Number, Amt_Paid)
RECEIPT(Member_ID, Receipt_Date, Dues_Received)
(a) Foreign keys are not indicated in these relations. Decide which attributes are foreign keys and justify your decisions. (b) Draw an E-R diagram for these relations, using your answer to part “a”. (c) Explain the assumptions you made about cardinalities in your answer to part “b”. Explain why it is said that the E-R data model is more expressive or more semantically rich than the relational data model.
6. Consider the following functional dependencies:
Applicant_ID –> Applicant_Name
Applicant_ID –> Applicant_Address
Position_ID –> Position_Title
Position_ID –> Date_Position_Opens
Position_ID –> Department
Applicant_ID + Position_ID –> Date_Applied
Applicant_ID + Position_ID + Date_Interviewed –> (Nothing)
(a) Represent these attributes with 3NF relations. Provide meaningful relation names. (b) Represent these attributes using an E-R diagram. Provide meaningful entity and relationship names.
7. Suppose you were designing a file of student records for your university’s placement office. One of the fields that would likely be in this file is the student’s major. Develop a coding scheme for this field that achieves the objectives outlined in Chapter 10 for field coding.
8. Suppose you created a file for each relation in your answer to question “3” above. If the following queries represented the complete set of accesses to this database, suggest and justify what primary and secondary key indices you would build.
(a) For each PART in Item_Number order list in Vendor_ID, sequence all the vendors and their associated prices for that part. (b) List all PART RECEIPTs, including related PART fields for all the parts received on a particular day. (c) For a particular VENDOR, list all the PARTs and their associated prices that VENDOR can supply.
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