Extendible hashing—a fast access method for dynamic files
ACM Transactions on Database Systems (TODS)
Database abstractions: aggregation and generalization
ACM Transactions on Database Systems (TODS)
CODASYL Data-Base Management Systems
ACM Computing Surveys (CSUR)
Comments on advantages of the relational view
SIGFIDET '74 Proceedings of the 1974 ACM SIGFIDET (now SIGMOD) workshop on Data description, access and control: Data models: Data-structure-set versus relational
The relational and network approaches: Comparison of the application programming interfaces
SIGFIDET '74 Proceedings of the 1974 ACM SIGFIDET (now SIGMOD) workshop on Data description, access and control: Data models: Data-structure-set versus relational
Remotely-sensed geophysical databases: experience and implications for generalized DBMS
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
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This paper compares the database model specified by the CODAYSL Data Definition Language Committee in its 1978 Journal of Development and the prior model, known familiarly as the CODASYL DBTG model, as specified in 1973 and 1971. The primary achievement of the 78 model appears to be increased potential for data independence by separation of external model and internal model considerations. The external model is described by a DDL; the internal model is described by a DSDL. Additionally, there is enhanced potential for data integrity via more explicit expression of data integrity constraints in the DDL. Conversion of a database from 73 model CODASYL DBMS support to 78 model support is discussed with emphasis on DSDL capabilities. The range of options in the DSDL open to the database designer for specifications of internal storage structures is surveyed. Several conclusions are drawn regarding implementation of support for the 78 model.