Dependency Preservation

Dependency Preservation is an important concept in database normalization that ensures all functional dependencies of a relation remain valid even after the relation is decomposed into smaller tables. When a large table is divided to reduce redundancy and improve design, it is necessary to make sure that the original constraints and rules between attributes are not lost. If all functional dependencies can be enforced directly on the decomposed tables without performing a join operation, the decomposition is said to be dependency preserving. This helps maintain data integrity, reduces complexity, and improves efficiency in database management. A good database design aims to achieve both lossless decomposition and dependency preservation to ensure accuracy and consistency of data. 

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