Oracle DBMS Interview Questions and Answers - 2

Question: 6

What is the standard normal form for most Online Transaction Processing (OLTP) databases?

3NF is the standard normal form for most OLTP databases.

Question: 7

What is trivial functional dependency?

A trivial function dependency is the situation, which shows a relation between an attribute with a superset of itself such that the attribute is dependent on the superset.

Question: 8

What are the types of normalization?

There are six different normal forms, which are given as follows:

First Normal Form (1NF) – A relation R is in 1NF if and only if all the underlying domains contain atomic values only.

Second Normal Form (2NF) – A relation R is in 2NF if and only if it is in 1NF and every non key attribute is fully functionally dependent on the primary key.

Third Normal Form (3NF) – A relation R is in 3NF if and only if it is in 2NF and every non key attribute is non transitively dependent on the primary key.

Boyce Codd Normal Form (BCNF) – A relation R is in BCNF if and only if every determinant is a candidate key.

Fourth Normal Form (4 NF) – A relation R is in 4NF if and only if there exists multi valued dependency in R, say A >> B, then, all the attributes of R are also functionally dependent on A.

Fifth Normal Form ( 5 NF) – A relation R is in 5NF or Project Join Normal Form (PJNF) if and only if every join dependency is implied by candidate keys.