Accession Number : ADA138117

Title :   The Operator Mapping between Relational Algebra Operators and CODASYL Based Databases Managed by a CODASYL DBMS.

Descriptive Note : Master's thesis,


Personal Author(s) : Nicely,D J

PDF Url : ADA138117

Report Date : Dec 1983

Pagination or Media Count : 115

Abstract : This thesis is an example of a mapping of a relational algebra query onto a network database. It consists of the requirements, definition, design and implementation of two generic COBOL programs for implementing such a mapping. The first program STOREMAP uses a batch input file to build a data dictionary, on the original network database, which defines the relations of which relational algebra queries may be made. This input file is created by the Data Base Administrator who is the most knowledgeable of the structure of the network database and the relations which would be useful to the databases's users. The second program NETTOREL uses the defined relations in the data dictionary and relational algebra queries created by a user to generate a result relations. Data to be included in a result relation is determined by the data dictionary's definition of the relations contained in an associated query and the criteria set by that query. This original effort shows that the theory for such an operator mapping is valid. Further efforts would be needed to make this implementation user friendly and therefore useful. (Author)

Descriptors :   *Data bases, *Data management, *Network analysis(Management), Interfaces, Input output processing, Data processing, Data links, Man computer interface, Batch processing, Files(Records), Operators(Personnel), Computer logic, Mapping, User needs, Theses

Subject Categories : Administration and Management

Distribution Statement : APPROVED FOR PUBLIC RELEASE