# What is the difference between 3NF and Boyce Codd Normal Form?

## What is the difference between 3NF and Boyce Codd Normal Form?

BCNF is an extension of 3NF and it is has more strict rules than 3NF. Also, it is considered to be more stronger than 3NF. This relation is in BCNF as it is already in 3Nf (there is no prime attribute deriving no prime attribute) and on the left hand side of the functional dependency there is a candidate key.

**Is BCNF always 3NF?**

Key Points – If a relation is in BCNF, then 3NF is also satisfied. If all attributes of relation are prime attribute, then the relation is always in 3NF. A relation in a Relational Database is always and at least in 1NF form.

**What is the relationship between the third normal form 3NF and the Boyce Codd Normal Form BCNF )?**

BCNF is an extension to Third Normal Form (3NF) and is slightly stronger than 3NF. A relation R is in BCNF, if P -> Q is a trivial functional dependency and P is a superkey for R….Boyce–Codd Normal Form (BCNF)

Ground | Begin_Time | End_Time |
---|---|---|

G02 | 08:00 | 09:00 |

### Why is BCNF stricter than 3NF?

BCNF is stricter than 3NF because each and every BCNF is relation to 3NF but every 3NF is not relation to BCNF. 4. BCNF non-transitionally depends on individual candidate key but there is no such requirement in 3NF. Hence BCNF is stricter than 3NF.

**What are the advantages of Boyce Codd Normal Form over other normal forms?**

It is a more restricted form of normalization so that the database does not end in anomalies. The business rules expressed in functional dependencies are enforced using keys, and BCNF ensures that it is correctly followed.

**What is Boyce Codd Normal Form with example?**

Boyce–Codd normal form (or BCNF or 3.5NF) is a normal form used in database normalization. It is a slightly stronger version of the third normal form (3NF). If a relational schema is in BCNF then all redundancy based on functional dependency has been removed, although other types of redundancy may still exist.

## When Boyce Codd Normal Form should be applied?

Boyce–Codd normal form (or BCNF or 3.5NF) is a normal form used in database normalization. It is a slightly stronger version of the third normal form (3NF). BCNF was developed in 1974 by Raymond F….3NF table always meeting BCNF (Boyce–Codd normal form)

Rate type | Court | Member flag |
---|---|---|

PREMIUM-A | 2 | Yes |

PREMIUM-B | 2 | No |

**What is the purpose of Boyce Codd Normal Form?**

BCNF was developed in 1974 by Raymond F. Boyce and Edgar F. Codd to address certain types of anomalies not dealt with by 3NF as originally defined. If a relational schema is in BCNF then all redundancy based on functional dependency has been removed, although other types of redundancy may still exist.

**What is the need of Boyce Codd Normal Form?**

### Is 3NF always dependency preserving?

It is always possible to find a dependency-preserving lossless-join decomposition that is in 3NF. A database design is in 3NF if each member of the set of relation schemas is in 3NF. We now allow functional dependencies satisfying only the third condition.

**What is 3NF in the DBMS?**

Third normal form (3NF) is a database schema design approach for relational databases which uses normalizing principles to reduce the duplication of data, avoid data anomalies, ensure referential integrity, and simplify data management. It was defined in 1971 by Edgar F.

**What is 3NF example?**

A relation that is in First and Second Normal Form and in which no non-primary-key attribute is transitively dependent on the primary key, then it is in Third Normal Form (3NF). Note – If A->B and B->C are two FDs then A->C is called transitive dependency.

## What is the difference between BCNF 2NF and 3NF?

In a table that is in the BCNF normal form, for every non-trivial functional dependency of the form A → B, A is a super-key whereas, a table that complies with 3NF should be in the 2NF, and every non-prime attribute should directly depend on every candidate key of that table.

**What is the difference between 4NF and 5NF?**

4NF (Fourth Normal Form) Rules. If no database table instance contains two or more, independent and multivalued data describing the relevant entity, then it is in 4 th Normal Form. 5NF (Fifth Normal Form) Rules. A table is in 5 th Normal Form only if it is in 4NF and it cannot be decomposed into any number of smaller tables without loss of data.

**Is it possible to get 3NF table/relation without BCNF?**

A table/relation not in BCNF is subject to anomalies such as the update anomalies mentioned in the pizza example by another user. Unfortunately, 3NF can always be obtained.

### What is the 3NF problem?

The 3NF problem : The partial key/prime attribute “Court” is dependent on something other than a superkey. Instead, it is dependent on the partial key/prime attribute “Rate Type”. This means that the user must manually change the rate type if we upgrade a court, or manually change the court if wanting to apply a rate change.