An architecture for high-level language database extensions

ABSTRACT

This paper describes an architecture for a set of database extensions to the existing high-level languages. The scheme described forms an architecture in the sense that it is not based on any particular language: its constructs and functions, or some suitable subset of them, may be mapped into the concrete syntax of a number of distinct languages, among them COBOL and PL/I. The architecture includes both the means for specifying the programmer's view of a database (i.e. for defining the external schema) and the means for manipulating that view. A significant feature is that the programmer is provided with the ability to handle all three of the well-known database structures (relational, hierarchical, network), in a single integrated set of language extensions. Another important aspect is that both record- and set-level operations are provided, again in an integrated fashion. The objectives of the architecture are to show that it is possible for relational, hierarchical and network support to co-exist within a single language, and also, by providing a common framework and treating the three structures in a uniform manner, to shed some new light on the continuing debate on the relative merits of each.The paper is intended as an informal introduction to the architecture, and to this end includes several illustrative examples which make use of a PL/I-based concrete syntax.

REFERENCES

• 1: C. W. Bachman: "ANSI/X3/SPARC Study Group on Data Base Systems: Summary of Current Work" (January 1974).
• 2: ANSI/X3/SPARC Study Group on Data Base Systems: Interim Report (8 Feb 1975).
• 3: Data Base Task Group of CODASYL Programming Language Committee: Final Report (April 1971).
• 4: Data Base Language Task Group of CODASYL Programming Language Committee: COBOL Data Base Facility Proposal (March 1973).
• 5: Proceedings of IFIP TC-2 Special Working Conference: A Technical In-Depth Evaluation of the DDL (Namur, Belgium, 13-17 Jan 1975). North-Holland (1975).
• 6: E. F. Codd, A relational model of data for large shared data banks, Communications of the ACM, v.13 n.6, p.377-387, June 1970 [doi>10.1145/362384.362685]
• 7: E. F. Codd: "A Data Base Sublanguage Founded on the Relational Calculus". Proc. 1971 ACM SIGFIDET Workshop on Data Description, Access and Control.
• 8: E. F. Codd: "Relational Completeness of Data Base Sublanguages". In Data Base Systems, Courant Computer Science Symposia Series Vol. 6, Prentice-Hall (1972).
• 9: E. F. Codd: "Recent Investigations in Relational Data Base Systems". Proc. IFIP Congress 1974, North-Holland.
• 10: E. F. Codd , C. J. Date, Interactive support for non-programmers: The relational and network approaches, Proceedings of the 1974 ACM SIGFIDET (now SIGMOD) workshop on Data description, access and control: Data models: Data-structure-set versus relational, p.11-41, May 01-03, 0074, Ann Arbor, Michigan [doi>10.1145/800297.811529]
• 11: C. J. Date, An Introduction to Database Systems, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1991
• 12: R. W. Engles: "An Analysis of the April 1971 DBTG Report". Proc. 1971 ACM SIGFIDET Workshop on Data Description, Access and Control.
• 13: R. W. Engles: "Currency and Concurrency in the COBOL Data Base Facility". Proc. IFIP TC-2 Working Conference on Modelling in Data Base Management Systems, Freudenstadt, Germany, January 1976 (to appear).
• 14: IBM: Information Management System/Virtual Storage General Information Manual (IBM Form No. GH20-1260).
• 15: G. M. Nijssen: "Data Structuring in DDL and Relational Data Model". In Data Base Management Systems (ed. Klimbie and Koffeman), Proc. IFIP TC-2 Working Conference, Cargese, Corsica 1974 (North-Holland).
• 16: G. Held, M. Stonebraker: "Networks, Hierarchies and Relations in Data Base Management Systems". Proc. ACM Pacific Conference, San Francisco, April 1975.
• 17: R. W. Taylor: "Report on IFIP TC-2 Special Working Conference: A Technical In-Depth Evaluation of the DDL (Namur, Belgium, 13-17 Jan 1975)".
• 18: ANSI/ECMA: BASIS/1-12 (Draft PL/I Standard), July 1974.
• 19: R. C. Summers, C. D. Coleman and E. B. Fernandez: "A Programming Language Extension for Access to a Shared Data Base." Proc. ACM Pacific Conference, San Francisco, April 1975.