Wednesday, September 30, 2015

Which Normal Form is adequate for Database Design

Which Normal form is considered adequate for Relational database design / DBMS ?
A. 2NF
B. 3NF

C. 3.5NF or BCNF
D. 4NF
Answer: B (3rd Normal Form (3NF)
Explanation: A relational database table is often described as "normalized" if it is in the Third Normal Form because most of the 3NF tables are free of insertion, update, and deletion anomalies. Third normal form is a normal form used in normalizing a database design to reduce the duplication of data and ensure referential integrity by ensuring that:
1.  the entity is in second normal form and
2. all the attributes in a table are determined only by the candidate keys of that table and not by any non-prime attributes