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Boyce-Codd Normal Form or BCNF is an extension to the third normal form, and is . In the picture below, we have tried to explain BCNF in terms of relations. Boyce-Codd Normal Form (BCNF) is a design guideline used in relational database theory which aims at increasing database integrity. Normalization in DBMS: 1NF, 2NF, 3NF and BCNF in Database .. And also one thing before using those keys it is better to briefly explain about the keys so it is.

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Maybe not suitable for an 8-year old child but hope it helps.

Boyce–Codd normal form

This process is known as normalization. For case 13NF takes care of. Bcnc superkey whose size number of columns is the smallest is called as a candidate key. Here is what I understand:. The various forms of database normalization are useful while designing the schema of a database in such a way that there is no data replication which may possibly lead to inconsistencies.

Foreign Key references the primary key of another Table! It’s a dependency on something other than a whole candidate key. Rose Cooper December 4, One student can enrol for multiple subjects.

Columns in a table bdnf are NOT used to identify a record uniquely are called non-key columns. In this tutorial, you are going to see the detailed description on how to create and execute the Just a question, trying to understand this. Data integrity may not retain in the denormalization and redundancy added into this.

How to become a Data Analyst with no Experience. This table also satisfies the 2nd Normal Form as their is no Partial Dependency. In the table above: Normalization applies to get rid of the dependencies and having minimal fields in the data table.


In the daily use of SQLite, you will need some administrative tools over your database. Chash Java P. Each student may enrol in multiple courses. The above is a simplified example bcnnf how database normalization works. If you are working with or designing an OLTP application where more independent tables are actually given a benefit of storing esplain in the more optimal way. Expllain, think about the case when there are hundreds of courses and instructors and for each instructor, we have to store not just the mobile number, but also other details like office address, email address, specialization, availability, etc.

As for the quote in my original question, google “so help me Codd” to find the origin for the quotes. Yet, the above way of thinking helps to understand how some anomaly is percolated even after 2nd and 3rd NF. Instructor’s name Course code Prof. There are other techniques available like star schema, denormalization etc. Dimension table contains dimensions of a fact.

The second point sounds a bit tricky, right? A composite bcng is a primary key composed of multiple columns used to identify a record uniquely In our database, we have two people with the same name Robert Phil, but they live in different places. Summary Database designing is critical to the successful implementation of a database management system that meets the data requirements of an enterprise system.

So, that becomes our primary key. Gene Jacket December 4, 7: Teacher Date Room Mr Smith In other words BCNF requires that every nontrivial determinant is a superkey even its dependent attributes happen to be part of a key. A better method would explaib to store the courses separately. If you look at the answers to this really old question, you’ll see that none of the highly rated ones are vague or imprecise.


A table is said bcjf be in fourth normal form if there is no two or more, independent and bnf data describing the relevant entity. Basically, we store the instructors separately and in the course table, we do not store the entire data of the instructor. Teacher Date Mr Smith Find a published academic textbook definition, not a bunch of vague rumours.

Table 1 and Table2.

What is Boyce-Codd Normal Form (BCNF)? – Definition from Techopedia

Also, observe that each row stores unique information. This was the first time the notion of a relational database was published. Dimension table is denormalized. The key is Pizza, Toppingand the column ToppingType is dependent upon the key and nothing but the key, but it is not dependent on the whole key. Now if we upgrade the court xeplain can guarantee the rate ezplain will reflect this change, and we cannot charge the wrong price for a court.

Can database normalization reduce number of tables?

In such a situation, we will have to make edits in 2 places. Kristi Explani December 5, Wanda Lee December 4, That “nothing but the key” phrase is less than useless. Al Alvarez December 5, 9: Janice Garcia December 4,