A system for conceptual and logical database design

The general scheme of a system for a conceptual and logical database design is described. The database management systems, becoming a convenient way of creating a database, are frequently used as a new mode of access to data, but not as a means of common possession of them. This is due to the great importance of database structure. The principal consequences of an unsuitable structure are the unmeasurable expenses for its modification which must be realized as soon as the inconsistency of this structure is found. Hence, one important factor in the exploration of database is the existence of a methodology and a software which can be used for automation of the database schema design. The proposed system consists of two phases : conceptual design and logical design (see Figure). In the conceptual design phase there are the following stages: the information requirements analysis, views conceptual design and views integration. The information requirements analysis is the first stage of the database methodology. During this stage the designer collects the user's information requirements concerning those parts of the organization which are to be automatized by means of a database applications, and formalizes them into descriptions of data, operations and restrictions. The information requirements analysis is related to the elaboration of: