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. Functional dependency is a constraint between two sets of attributes in a relation from a database. Pull determines the Buena, 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 election 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 1 NFG? 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 identify the rows in the table 12. What are the requirements for INFO?
The table is a relation; that is, it meets all the requirements for the INFO. There is no partial dependency in the table 13. What is INFO? It is in INFO and contains no transitive dependency 14. What is BACON? It is in info and every determinant is a candidate key 15. List the naming rules used in this book. A name can include up to 128 characters, numbers, or symbols A name must start with one of [a-z], [A-Z], @, #, or letter characters from other on-English languages defined by Unicode standard 2. The subsequent symbols can be the combination a-z, A-Z, numbers, or letter characters from other non-English languages defined by Unicode standard 2. 0 A name cannot use a reserved key word such as System for an object An object name cannot use embedded spaces except for a database 16. What do you do with the delimiters ” ” and 0? If you have to use names that do not follow the naming rules they must be in ” ” or 0. 17. When a name starts with the symbol @, what does the symbol represent? It represent a local variable or parameter 18.
Use represent intensifying relationship, such as Student has option to have an advisor, so no checkmate under Is Required in the table design of Azure 19. Use an example to represent a nonspecific relationship with tables. Many-to-many M:N represented with I:M and a I:N, such as Student and Class, where Student_Class contains key from both Class and Student 20. How do you implement a referential constraint? By creating the primary and foreign key restraint; with defining foreign key constraint, you can specify the parent table and the column shared by the primary key and the foreign key