Database Reference
In-Depth Information
9. Explain data, entity, domain and referential integrity.
10. What are the differences between candidate and primary key?
11. Write short note on NULL constraints.
12. What is the differences between table and view?
13. Explain various relational algebra operators with suitable example.
14. Explain Key constraints.
15. What is Foreign keys (FK)?
Chapter 5
NORMALIZATION
5.1 NON-LOSS DECOMPOSITION
Non-loss decomposition is process in which relations/tables are divided in such a manner
that they can be recombined without loss of information. The relational model permits us
to join relations/tables in various ways by linking attributes. The process of getting a fully
normalized data model includes removing redundancy. Relations are divided in such a way
that the resultant relations can be recombined without losing any of the information. This
is the principle of lossless decomposition.
5.2 FUNCTIONAL DEPENDENCY
Functional dependency is a relationship between two attributes such that the value of
one attribute finds the value in the other. Functional dependency is extremely useful
