D1: DB Project Analysis & Query : Develop a reasonable and realistic plan and ou
ID: 3855761 • Letter: D
Question
D1: DB Project Analysis & Query: Develop a reasonable and realistic plan and outline the steps to accomplish the integrated project by the end of the course. You can also refer to Garden Glory project questions in §1~3 of the Textbook (at the end of each chapter).
1. What are the modification problems that are likely to occur if Garden Glory attempts to maintain the list below in a spreadsheet?
2. Using these data presented in the list, state assumptions about functional dependencies among the columns of data. Justify your assumptions on the basis of these sample data and also on the basis of what you know about service businesses. Indicate what assumptions need to be checked with the users (GG) and what suggestions you may have about the determinants/keys (e.g., do you need a surrogate key?)
3. Based on the above analysis and assumptions, split the sample list into tables such that each has only one theme. Demonstrate that the modification problems you identified in E have been eliminated.
Explanation / Answer
1. Three types of modifications are likely to occur; they are
2. Many functional dependencies are defined here. They are;
PropertyName -> PropertyType
(PropertyName, Street) -> (PropertyType, City, Zip)
(PropertyName, City) -> (PropertyType, Street, Zip)
(PropertyName, Zip) -> (PropertyType, Stree, City)
(PropertyName, Description, ServiceDate) -> Amount
They are of just coincidences. Hence Surrogate Key is required here as,
PropertyID -> (PropertyName, PropertyType, Street, City, Zip)
(PropertyName, Description, ServiceDate) -> Amount
3.
Property(PropertyID, PropertyName, PropertyType, Street, City, Zip)
Service(ServiceID, ServiceDate, Description, Amount, PropertyID)
PropertyID has been set as foreign key in Property
the modifications problems has been resolved
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