MIS 3500 Database Management Systems * Asper School of Business * Instructor: Bob Travica
Homework 1: AnalyzingKeys
Updated January 2018
Database systems depend significantly on key attributes (keys) that uniquely identify reality aspects that are tracked by these systems. Relational DB systems are especially sensitive to correct design of keys (a famous database theorist proposed that developers should swear in “key, key, and nothing but the key”).
Sometimes a key identifies a kind of objects. For example, the product number identifies a kind of products, such as personal computers (as opposed to tablet devices). At other times, a key identifies each individual object; for example, a particular personal computer is identified by a serial number, a unique, never repeated sequence of numerals.
Keys are often labelled with terms "number" or "ID" (short of "identification"). The data type behind the term "number" may or may not be numeric; for example, SaleNumber can be an integer assigned to a sale transaction, while VIN (Vehicle Identification Number) is a combination of numbers, letters and special characters.
Your task is to pick out nine (9) different attributes that are or can be used as keys in database systems. Even a brief look at everyday situations can help you accomplish this (for example, look at any receipt from shopping). Once you pick a key attribute, you need to do the following:
1) Name the attribute (example: StudentID).
2)Give an example of the attribute’s value (real or made up sensibly; example: 2348765).
3) State a relationship between your attribute and at least one other attribute that you believe really exists or could exist in a database system and/or in business (non-key attribute) (example: StudentLastName).
You need to supply these three items for each of your nine keys.
You can choose any format that works for you; for example, a table, standard text using simple sentences, or a bullet form. In any case, make sure that each of the 3 points above is clearly marked and addressed.
It is possible to pack the whole answer on one page.
Submit your work to UMLearn, the folder Homework 1.
Note: The attributes used in class notes are not eligible (e.g., CustomerID, OrderID, ItemID, StudentNumber, VIN…). Extend your thinking!