Tag: database normalization
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Database Normalization (5NF)
Fifth Normal Form (5NF), also known as Project-Join Normal Form (PJNF), is a level of database normalization that further refines the structure of a database to eliminate certain types of redundancy and anomalies. It addresses cases where information is redundantly stored across multiple rows due to a combination of candidate keys and overlapping multivalued dependencies.…
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Database Normalization (4NF)
Fourth Normal Form (4NF) is a level of database normalization that addresses multi-valued dependencies. It ensures that there are no non-trivial multi-valued dependencies between candidate keys and non-key attributes. To achieve 4NF, a database should already be in BCNF. Let’s explore how to use 4NF normalization with an example: Example: Product Supplier Database Consider a…
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Database Normalization (BCNF)
Boyce-Codd Normal Form (BCNF) is a higher level of database normalization that addresses certain anomalies that might still exist in databases normalized up to 3NF. To achieve BCNF, a database should already be in 3NF. BCNF ensures that for every non-trivial functional dependency X -> Y, X must be a superkey. Let’s continue using the…
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Normalizing Database (3NF)
Normalizing a database to the Third Normal Form (3NF) involves eliminating transitive dependencies and ensuring that non-key attributes are only dependent on the primary key. To achieve 3NF, the database should already be in 2NF. Let’s continue with the example of the Student Course Registration Database and normalize it to 3NF: Recap: Current Database State…
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Normalizing Database (2NF)
Normalizing a database to the Second Normal Form (2NF) involves removing partial dependencies and ensuring that all non-key attributes are fully functionally dependent on the entire primary key. To achieve 2NF, you must first ensure that your database is in 1NF and then address partial dependencies. Let’s go through the process of normalizing a sample…
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Normalizing Database (1NF)
Normalizing a database involves organizing and structuring it to reduce redundancy and improve data integrity. The process of normalization involves several normal forms, with the first normal form (1NF) being the foundational step. To bring a database to 1NF, you need to ensure that certain rules are followed. Here’s how you can normalize a database…