A storage structure definition language for Codasyl Data Bases

This paper proposes a language for the definition of the physical storage structures in a Codasyl Data Base.The language is based on the idea of using a generalized model of the storage structures, called Virtual Paged Memory, which is capable of expressing many of the features which characterize the storage structures of many existing systems. This model is used as an intermediate level between the DDL-schema and the physical database.A critical comparison between the proposed approach and the BCS/CODASYL DDLC DBWAG proposal for a tentative standard of a storage schema definition language is also presented.