Chapter 3: Table Normalization and Windows Azure SQL Database
Chapter 3: Table Normalization and Windows Azure SQL Database
Review Questions
1. What are the conditions for a table to be a relation? Each cell in a table must contain a single value, there should be no duplicated rows, and all the cells in a column must contain the same type of data
2. How do you link a table to another table? Link tables based on a relationship connecting the entities with common column in each table
3. What is functional dependency? Give an example of functional dependency. a functional dependency is a constraint between two sets of attributes in a relation from a database. PubID determines the pubName, City, State, and Country.
4. What is a primary key? A candidate key to uniquely identify other columns in the relation
5. What is a foreign key? A column or a set of columns whose values match the values of the primary key in another relation
6. Describe update anomalies by using an example. . Membership fees needs to increase to Soccer; all students in Soccer will need to change for all rows and will accumulate process for large table
7. Describe insertion anomalies by using an example. . Inserting a new class requires student and class id so new classes cannot be added
8. Describe deletion anomalies by sing an example. . Deletion of a student after graduation causes deletion of other information in the same rows, such as courses, clubs, and etc.
9. Why do tables need to be normalized? Helps eliminate modification anomalies and reduce data redundancy
10. Why is the highest-level normalization not always desirable? There is no general rules that will tell us which business requirements can be implemented during the design stage and which ones should be implemented in the application programs
11. What are the requirements for 1NF? Each cell in the table contains a single value, each column has a unique column name and all the data entries in the column have the same data type, and no duplicate rows; primary key is used uniquely
Review Questions
1. What are the conditions for a table to be a relation? Each cell in a table must contain a single value, there should be no duplicated rows, and all the cells in a column must contain the same type of data
2. How do you link a table to another table? Link tables based on a relationship connecting the entities with common column in each table
3. What is functional dependency? Give an example of functional dependency. a functional dependency is a constraint between two sets of attributes in a relation from a database. PubID determines the pubName, City, State, and Country.
4. What is a primary key? A candidate key to uniquely identify other columns in the relation
5. What is a foreign key? A column or a set of columns whose values match the values of the primary key in another relation
6. Describe update anomalies by using an example. . Membership fees needs to increase to Soccer; all students in Soccer will need to change for all rows and will accumulate process for large table
7. Describe insertion anomalies by using an example. . Inserting a new class requires student and class id so new classes cannot be added
8. Describe deletion anomalies by sing an example. . Deletion of a student after graduation causes deletion of other information in the same rows, such as courses, clubs, and etc.
9. Why do tables need to be normalized? Helps eliminate modification anomalies and reduce data redundancy
10. Why is the highest-level normalization not always desirable? There is no general rules that will tell us which business requirements can be implemented during the design stage and which ones should be implemented in the application programs
11. What are the requirements for 1NF? Each cell in the table contains a single value, each column has a unique column name and all the data entries in the column have the same data type, and no duplicate rows; primary key is used uniquely