Experience with data translation over the last two years has resulted in a definite set of requirements for the normalized representation of data when used as an intermediate form during the process. The logical requirements pertain to the ability to represent a class of data structures including networks. The implementation requirements include the specification of two physical representations termed as the Restructurer Internal Form and the Interchange Form.Recent investigations with the Normal Forms of the relational model have shown that1. they satisfy the logical requirements2. a complete normalization to the third Normal Form requires excessive dependency data and results in reducing the restructuring operation to an identity transformation.3. normalization is not conducive to localizing the restructuring operations in the translator4. the first Normal Form used as a vehicle for translation poses problems with specification of keys and in handling networks.To alleviate the difficulties of normalization, a Modified Normal Form, similar to the First Normal Form, was designed and investigated. On the basis of the accessing, manipulation and processing requirements in the current model of data translation, it is concluded that a software system must be designed to work with the relational Normal Forms and their modified versions.

The problems associated with file design have recently received increased attention. One approach to their solution has been the development of file models. These models can be employed to study alternate file structures and aid the file design process. In this paper, a single model and cost function is developed to characterize most of the file structure alternatives and the selection of file structures for a design problem is automated. A file design system is developed that can be used by a file designer to select good file organizations from a large number of alternatives. The computer program which implements the model uses analytic optimization techniques to select file organizations. The output of the design system is a class of file structures specified by its average characteristics and the details of the actual file structure can be determined by simulation or other techniques.