The determination of functional dependencies is an important part of designing databases in the relational model, and in database normalization and denormalization.
The tables in the warehouse are heavily indexed and optimized using denormalization, which combines multiple tables into one to minimize performance penalty due to table joins.
When compared to a highly normalized transactional schema, the snowflake schema's denormalization removes the data integrity assurances provided by normalized schemas.
A standard piece of database design guidance is that the designer should create a fully normalized design; selective denormalization can subsequently be performed, but only for performance reasons.
