The following is the database schema used to track blood donations. The database has been in use for several years and contains thousands of entries. Primary keys are RID in Receptionist, DID in the donor, BID in Blood, NID in Nurses, PatientID in Transfusions and foreign keys carry the same names as the primary keys they reference.

Receptionist (RID, Name, Address, Phone#)

Donor (DID, Name, Address, Phone#, SSN, gender, DOB)

Blood(BID, Blood_type, Cost, DID, NID)

Nurses(NID, Name, Address, Phone#)

Transfusions(PatientID, Date, Trans#, BID)

Implement the following database refactoring requests by using the appropriate refactoring pattern(s) and describing the process of accomplishing the refactoring requests including (for each used refactoring):

1. name of the refactoring pattern chosen

2. motivation: why did you choose it for this database?

3. schema update mechanics: no need to include triggers but do include SQL commands needed to achieve the desired objective

4. data migration mechanics: again, no need to include triggers but do include SQL commands needed to achieve the desired objective

Please note that some of the following refactoring requests may require the application of multiple refactoring pattern(s). You are expected to discuss the refactoring pattern(s) required to achieve each refactoring request in the proper order. Show the affected relations in the schema after each refactoring. 1. The primary key in the Donor relation is too hard to reference when checking donors in and collecting blood. The decision is made to use a composite key of phone# and name instead. 2. Since donors may donate every 60 days, a collection date needs to be added to the blood relation.