On the semantics of data bases: The semantics of data definition languages

Abstract

As next step to complete the semantic definition of a data base system we have to consider a storage. This is a function from locations to values and no longer to value ranges. After we have defined so far how all the possible structures can be implemented, it is to be defined by which mechanism the locations are allocated to individual data. It has to be assumed that no location is allocated to different data at one moment, i.e. all allocated data must be independent. All this considerations are affected by the DML. In the framework proposed in this paper this interface between the DDL and DML, the role of the user working area, and their implementation dependencies can be handled in a unique manner which is nevertheless appropriate for each aspect. Thus we can gain an integrated understanding of a data base and its functions.