In fourth normal form it should not contain two or more independent multi-v about an entity and it should satisfy “Third Normal form”.
Fifth normal form deals with reconstructing information from smaller pieces of information. These smaller pieces of information can be maintained with less redundancy.
Sure, I’d be happy to explain Fourth Normal Form (4NF) and Fifth Normal Form (5NF).
Fourth Normal Form (4NF): 4NF is a level of database normalization that builds upon the concepts of Third Normal Form (3NF). It deals with multi-valued dependencies. A table is in 4NF if and only if, for every one of its non-trivial multi-valued dependencies, the table has a superkey.
In simpler terms, a table is in 4NF if it doesn’t contain any non-trivial multi-valued dependencies. This means that if a table has multiple values for a single attribute (which could lead to data redundancy), those attributes should be placed in a separate table. This helps in minimizing redundancy and maintaining data integrity.
Fifth Normal Form (5NF): 5NF, also known as Project-Join Normal Form (PJNF), is a higher level of normalization that addresses certain types of redundancy that cannot be handled by 4NF. A table is in 5NF if and only if every join dependency in the table is implied by the candidate keys.
In simpler terms, 5NF deals with cases where a table has multiple overlapping candidate keys and certain dependencies between these keys. It ensures that there is no redundancy or data anomalies caused by these overlapping keys.
In summary, while 4NF deals with multi-valued dependencies, 5NF addresses join dependencies and ensures that the table structure is free from certain types of redundancy that could lead to anomalies. Both 4NF and 5NF aim to improve data integrity and reduce redundancy in the database schema.