Domain Key Normal Form In Dbms Ppt

It builds on the first three normal forms 1nf 2nf and 3nf and the boyce codd normal form bcnf.

Domain key normal form in dbms ppt. Dbms normalization 1. 1st 2nd 3rd boyce code normal form 4th 5th and domain key normal form. Normalization is also termed as canonical synthesis by the experts.

Normalization it is a technique for designing relational database tables to minimize duplication of information. The reason is that the insertion and updation anomalies are removed. The relation is not in 3rd normal form because in bc d neither bc is a super key nor d is a prime attribute and in b e neither b is a super key nor e is a prime attribute but to satisfy 3rd normal for either lhs of an fd should be super key or rhs should be prime attribute.

So the highest normal form of relation will be 2nd normal form. The constraints are verified by the domain and key constraints. But in this article we will discuss only about domain key normal form.

It is based on constraints domain constraint. For example 1st normal form is weaker than that of 2nd normal form. Domain key normal form dknf there is no hard and fast rule to define normal form up to 5nf.

Fourth normal form 4nf fourth normal form 4nf is a level of database normalization where there are no non trivial multivalued dependencies other than a candidate key. A table is in domain key normal form only if it is in 4nf 3nf and other normal forms.