Use of Join Dependency
- Join dependency helped in reducing the redundant data.
- It ensures data integrity and consistency as no spurious tuples get generated
- It makes the databases normalized
- It is used in the 5th normalization form to maintain the data consistency and normalization in the database.
Join Dependency in Database
Join Dependency means re-creating the original Table by joining multiple sub-tables of the given Table. It is a further generalization of MVD(multi-valued Dependencies).
- When a relation R can be obtained by joining the R1, R2, R3…, Rn where R1, R2, R3…, Rn are sub-relations of R, it is called a Join Dependency.
- R1,R2,R3…Rn are the sub-relations composed or derived from the relation R.