Difference Between 3NF and BCNF

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In this post, we will understand the difference between 3NF and BCNF.


  • There shouldn’t be any transitive dependency.

  • There shouldn’t be any non-prime attribute that depends transitively on a candidate key.

  • It is not as strong as BCNF.

  • It has high redundancy.

  • The functional dependencies are already present in INF and 2NF.

  • It is easy to achieve.

  • It can be used to achieve lossless decomposition.


  • For any relation A->B, ‘A’ should be a super key of that specific relation.

  • It is stronger than 3NF.

  • The functional dependencies are present in 1NF, 2NF and 3NF.

  • It has low redundancy in comparison to 3NF.

  • The functional dependencies may or may not be preserved.

  • It is difficult to achieve.

  • It is difficult to achieve lossless decomposition using BCNF.

Updated on 25-Mar-2021 06:31:13