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Normalization Process: Exercise 2: Step 1 IST2101 Step 1. Identify all the candidate keys of the relation. (Attorney, ClientNumber, MeetingDate)

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Presentation on theme: "Normalization Process: Exercise 2: Step 1 IST2101 Step 1. Identify all the candidate keys of the relation. (Attorney, ClientNumber, MeetingDate)"— Presentation transcript:

1 Normalization Process: Exercise 2: Step 1 IST2101 Step 1. Identify all the candidate keys of the relation. (Attorney, ClientNumber, MeetingDate)

2 Normalization Process: Exercise 2: Step 2 IST2102 Step 2. Identify all the functional dependencies in the relation. ClientNumber  ClientName When you are not certain about functional dependencies, consider the three modification operations in Chapter 1: insert, update, and delete. E.g., Update ClientName for ClientNumber 1000 Trivial dependency: (Attorney, ClientNumber, MeetingDate)  (ClientName, Duration)

3 Normalization Process: Exercise 2: Step 3 IST2103 Step 3. If any determinant is not a candidate key, the relation is not well formed. (Attorney, ClientNumber, MeetingDate) (Attorney, ClientNumber, MeetingDate)  (ClientName, Duration) ClientNumber  ClientName

4 Normalization Process: Exercise 2: Step 3 IST2104 Step 3. Examine the determinants of the functional dependencies. If any determinant is not a candidate key, the relation is not well formed. In this case: a.Place the columns of the functional dependency in a new relation of their own. CLIENT(ClientNumber, ClientName) b.Make the determinant of the functional dependency the primary key of the new relation. CLIENT(ClientNumber, ClientName) c.Leave a copy of the determinant as a foreign key in the original relation. MEETING(Attorney, ClientNumber, MeetingDate, Duration) ClientNumber: A foreign key and also part of primary key d.Create a referential integrity constraint between the original relation and the new relation. ClientNumber in MEETING must exist in ClientNumber in CLIENT

5 Normalization Process: Exercise 2: Step 4 IST2105 Step 4. Repeat step 3 as many times as necessary until every determinant of every relation is a candidate key. CLIENT(ClientNumber, ClientName) MEETING(Attorney, ClientNumber, MeetingDate, Duration) ClientNumber in MEETING must exist in ClientNumber in CLIENT Well-formed relational model design


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