Database Normalization: Explain 1NF, 2NF, 3NF, BCNF With Examples + PDF: The purpose of normalization is to make the life of users easier. Insertion, Updation and Deletion Anamolies are very frequent if database is not normalized. To understand these anomalies let us take an example of a Student . A relation is said to be in 2NF, if it is already in 1NF and each and every In the 3NF example,Stud_ID is super-key in Student_Detail relation.

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Sandra Bowen December 5, Further, if you observe, the mobile number now need not be stored 2 times. Instructor’s name Course code Prof.

Database Normalization: Explain 1NF, 2NF, 3NF, BCNF With Examples

Only one value per column 2NF: Maria Clark December 4, Hackr Team December 4, 7: There are wwith techniques available like star schema, denormalization etc. The above is a simplified example of how database normalization works. Granularity can be easily understood by the term of detail in a set of data.

Database Normalization is a technique of organizing the data in the database. Andrea Harris December 4, Gene Jacket December 4, 7: Rose Cooper December 4, Arcturus read through the article, still one of the better explanations for normalization out there. It is 1nv trivial functional dependency: For more detail, see wikipedia What is Composite Key?

There is no repetition. Boyce to develop the theory of Boyce-Codd Normal Form. Hence, at the end of the academic year, if student records are deleted, we will also lose the branch information.


Superkey basically determines each row uniquely. When developing the schema of a relational database, one dxample the most important aspect to be taken into account is to ensure that the duplication is minimized.

DBMS Normalization: 1NF, 2NF, 3NF and BCNF with Examples

Problems Without Normalization If a table is not properly normalized and have data redundancy then it will not only eat up extra memory space but will also 3jf it difficult to handle and update the database, without facing data loss. In the case of databases, we can say “The data depends on the key, the whole key and nothing but the key, so help me Codd”. Every column in your table relates only to witn table’s key — you wouldn’t have a column in a table that describes another column in your table which isn’t the key.

I shouldn’t be allowed to do that, because they’ve both got the ID of Mildred Russell December wigh, Minimizing the insertion, deletion, and update anomalies iii. Rose Potter December 5, 9: We have again divided our tables and created a new table which stores Salutations. Let us take an example.

What is Normalization? Explain 1NF, 2NF, 3NF and BCNF giving examples.

The reasons why we use data normalization are to minimize duplicate data, to minimize or avoid data modification issues, and to simplify queries.

In the next tutorial, we will discuss about the First Normal Form in details. The candidate key is employeeNumber.

Here, examlle we changed the name of the professor, we also had to change the department column. Entrepreneur, Coder, Speed-cuber, Blogger, fan of Air crash investigation!


There must not be any partial dependency of any column on the primary key. We will now more formally study it.

Database Normalization: Explain 1NF, 2NF, 3NF, BCNF With Examples

Wanda Lee December 4, For instance, suppose, if Prof. In some courts, a witness is asked if they will tell “The truth, the whole truth, and nothing but the truth, so help me God”; as God is considered to be the one with authority when it comes to knowing if you’re telling the truth. Suppose for a new admission, until and unless a student opts for a branch, data of the student cannot be inserted, or else we will have to set the branch information as NULL.

Consider a table that shows the database of a bookstore. This is Deletion anomaly. The answer should be self-contained, in other words.

The design needs to be modified in order to conform to the BCNF. This is not desirable since someone who is updating the database may remember to change the name of exmaple professor, but may forget updating the department value.

Francis Vega December 5, Just think about it in terms of the relationship between things. Similarly, if I ask you “what teacher has the ID ?