A relational view of the data independent accessing model

ABSTRACT

Efficiency is of paramount importance in very large databases. A principal technique for increasing efficiency is to define the user's view of the data independently of the storage structure so that the storage structure can be varied at will to improve performance. A widely accepted user view for this purpose is the relational model [3] and substantial progress has been made since its introduction. Far less research has been devoted to fundamental models of storage structures and the only comprehensive treatment is the Data Independent Accessing Model (DIAM) [1]. The DIAM, however, has seen limited application due, at least in part, to its use of the (less popular) entity set view of data. And despite the close correspondence between the relational and entity set views [2], little has been done to exploit their similarities. This paper attempts to show that the DIAM's relevance to contemporary research in database systems can be enhanced by viewing it through n-ary relations. To accomplish this, the paper first develops a redefinition of the DIAM String Level in terms of n-ary relations. It then appeals to the remaining levels of the DIAM to describe various relational implementation alternatives. The paper concludes that the utility of both the DIAM and the relational model is enhanced by this approach.

REFERENCES

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