5 NF is related to ______________.
5 NF is related to join dependency.
Fifth normal form (5NF), also known as project-join normal form (PJ/NF) is a level of database normalization designed to reduce redundancy in relational databases recording multi-valued facts by isolating semantically related multiple relationships. A table is said to be in the 5NF if and only if every non-trivial join dependency in that table is implied by the candidate keys.
Join dependency is a constraint on the set of legal relations over a database scheme.