1. What is Normalization?
It basically involves dividing larger tables down to smaller tables and to define the relationships between them. Basically a means of efficiently organizing data in a database. One thing is eliminating redundancy.
2. What is Insertion, Update and Deletion anomalies?
a. Insertion anomaly- It is a failure to place information about a new database entry into all the places in the database where information about the new entry needs to be stored.
b. Update Anomaly- Basically involves modifications that may be additions, deletions, or both. Really can be either deletion or insertion anomaly.
c. Deletion Anomaly- Is the failure to remove information about an existing database entry when it is time to remove that entry. For example: normalized database, information about an old to be gotten rid of entry needs to be deleted from only one place in the database but in an inadequately normalized database, information about that old entry might need to be deleted from more than one place.
3. What is the importance of Normalization? There are basically three major reasons why normalization is important, 1- is wasted space, 2- Resource usage, 3- data integrity.
4. Explain all the normal forms?
a. 1NF-1st Normal Form- Represents a relation and has no repeating groups.
b. 2NF-2nd Normal Form- No non-prime attribute in the table is functionally dependent of a subset or any candidate key.
c. 3NF-3rd Normal Form- Every non-prime attribute is non-transitively dependent on every candidate key in the table. The attributes that do not contribute to the description of the primary key are removed from the table. In other words, no transitivity dependency is allowed.
d. EKNF- Elementry Key- Every non-trivial functional dependency in the table is either the dependency of an elementary key attribute or a dependency on a superkey
e. BCNK- Boyce Codd-