Why views do not provide logical data independence

Most information systems are subject to changing requirements that often necessitate alterations of the underlying database schema. Part of these alterations are information-preserving and can therefore be regarded as schema restructuring. One of the objectives of the relational model is to provide logical data independence, i.e., to insulate application programs and terminal users from the negative effects of information-preserving changes of the logical database schema. It is claimed that the relational view mechanism is crucial to achieve logical data independence. This paper argues that the relational view mechanism fails to fulfil this claim in both a theoretical and a practical sense