BCNF vs 4NF (4th Normalization). Database normalization is a technique, which is dealing with relational database management systems. The definition of 4NF differs from the BCNF definition only in the use of the decomposition schema satisfying only the restrictions on D there. Comparison of BCNF and 3NF. We have seen BCNF and 3NF. It is always possible to obtain a 3NF design without sacrificing lossless-join or.

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By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. I know that 3NF makes a database more efficient and oimitations data according to relevance, which is more logical, but are there other advantages? Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer.

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What is Fourth Normal Form (4NF)? – Definition from Techopedia

Third normal form 3NF includes the rules of the lower level normal form, such as second 2NF and first normal form 1NF. Normalization provides both advantages and disadvantages, some of them are mentioned below.


In each level of normalization a type of data redundancy same data present in more than once removed from the model. Once the redundancy is removed, it is easy to change the data since data is present in only one place.

database – Multivalued dependencies and BCNF/4NF – Stack Overflow

By applying business rules, there is a smaller chance in storing unwanted data in the table. Also there is less need for storing null values. In normalization we have to ask a lot of questions to business people, so our understanding of the business becomes stronger and requirements of the business are easy to capture. Normalization splits a entity into a smaller number of entities, so you will have more smaller tables, so it is easier for sorting, indexing and searching.

Difference Between BCNF and 4NF (4th Normalization)

Since there are many kf tables, you will have many clustered indexes, it will help you in query tuning. With many number tables and joins in between those tables slow down the performance of the database. A completely normalized database needs clear and broad understanding of the business, it takes more time to analyse and understand the business.


I hope this will help you.

Except a logical aspect – there is a performance one – you divide data to a smaller tables. One disadvantage, that I can think about is longer code – lots of joins to query tables.

Another one is that divided data is not the best option for OLAP processes, that is why sometimes you’ll see not normalized tables at Data Warehouse environments. Home Questions Tags Users Unanswered.

What are the advantages and disadvantages of Third normal form and Boyce-Codd normal form? Connor 16 1 2. Capturing complete business requirements: Data modification anomalies Insert, delete and update are reduced.

A normalized data model can be easier to modify and maintain. Disadvantages With many number tables and joins in between those tables slow down the performance of the database.

Having a large number of tables consumes more development time for implementation. Michael Cherevko 3