Denormalization has these disadvantages:
Denormalization usually speeds retrieval but can slow updates. This is not a real concern in a DSS environment.
Denormalization is always application-specific and needs to be re-evaluated if the application changes.
Denormalization can increase the size of tables. This is not a problem in Sybase IQ, because you can optimize the storage of column data. For details, see the IQ UNIQUE column constraint in CREATE TABLE statement and “MAX_QUERY_TIME option” in Reference: Statements and Options.
In some instances, denormalization simplifies coding; in others, it makes it more complex.