CODASYL
Encyclopedia
CODASYL is an acronym for "Conference on Data Systems Languages". This was a consortium formed in 1959 to guide the development of a standard programming language
that could be used on many computers. This effort led to the development of COBOL
and other standards.
CODASYL's members were individuals from industry and government involved in data processing activity. Its larger goal was to promote more effective data systems analysis, design, and implementation. The organization published specifications for various languages over the years, handing these over to official standards bodies (ISO
, ANSI
, or their predecessors) for formal standardization.
language and its activities in standardizing database interfaces. It also worked on a wide range of other topics, including end-user form interfaces and operating-system control languages, but these projects had little lasting impact.
The remainder of this section is concerned with CODASYL's database activities.
In 1965 CODASYL formed a List Processing Task Force. This group was chartered to develop COBOL language extensions for processing collections of records; the name arose because Charles Bachman
's IDS
system (which was the main technical input to the project) managed relationships between records using chains of pointers. In 1967 the group renamed itself the Data Base Task Group
, and its first report in January 1968 was entitled COBOL extensions to handle data bases.
In October 1969 the DBTG published its first language specifications for the network database model
which became generally known as the Codasyl Data Model. This specification in fact defined several separate languages: a data definition language
(DDL) to define the schema
of the database, another DDL to create one or more subschemas defining application views of the database; and a data manipulation language
(DML) defining verbs for embedding in the COBOL programming language to request and update data in the database. Although the work was focused on COBOL, the idea of a host-language independent database was starting to emerge, prompted by IBM
's advocacy of PL/I
as a COBOL replacement.
In 1971, largely in response to the need for programming language independence, the work was reorganized: development of the Data Description Language was continued by the Data Description Language Committee, while the COBOL DML was taken over by the COBOL
language committee. With hindsight, this split had unfortunate consequences. The two groups never quite managed to synchronize their specifications, leaving vendors to patch up the differences. The inevitable consequence was a lack of interoperability among implementations.
A number of vendors implemented database products conforming (roughly) to the DBTG specifications: the most well-known implementations were Honeywell
's Integrated Data Store (IDS/2), Cullinet's Integrated Database Management System IDMS
, Univac
's DMS-1100, and Digital Equipment Corporation's
DBMS32. Cullinet
, originally known as Cullinane Database Systems, obtained the technology from B.F. Goodrich. Cullinet was eventually sold to Computer Associates, which as of 2007 still sells and supports a version of IDMS.
ANSI
and ISO adopted the Codasyl database specifications under the name Network Database Language (NDL), with work taking place within the same working group (X3H2) as SQL
standardization. An ISO standard for NDL was ratified as ISO 8907:1987, but it never had any practical effect on implementations, and was formally withdrawn in 1998.
Some of the CODASYL committees continue their work today, but CODASYL itself no longer exists. The records of CODASYL were donated to the Charles Babbage Institute
and a catalog may be found at their website.
Interest in CODASYL gradually faded due to growing interest in relational database
s beginning in the early 1980s.
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
that could be used on many computers. This effort led to the development of COBOL
COBOL
COBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
and other standards.
CODASYL's members were individuals from industry and government involved in data processing activity. Its larger goal was to promote more effective data systems analysis, design, and implementation. The organization published specifications for various languages over the years, handing these over to official standards bodies (ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
, ANSI
American National Standards Institute
The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...
, or their predecessors) for formal standardization.
History
CODASYL is remembered almost entirely for two activities: its work on the development of the COBOLCOBOL
COBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
language and its activities in standardizing database interfaces. It also worked on a wide range of other topics, including end-user form interfaces and operating-system control languages, but these projects had little lasting impact.
The remainder of this section is concerned with CODASYL's database activities.
In 1965 CODASYL formed a List Processing Task Force. This group was chartered to develop COBOL language extensions for processing collections of records; the name arose because Charles Bachman
Charles Bachman
Charles William "Charlie" Bachman is an American computer scientist, who spent his entire career as an industrial researcher rather than in academia...
's IDS
Integrated Data Store
Integrated Data Store is a network database largely used by industry for its performance.IDS was designed by Charles Bachman at General Electric in the 1960s. It was not known to be easy to use or implement applications with, because it was designed to maximize performance using the hardware...
system (which was the main technical input to the project) managed relationships between records using chains of pointers. In 1967 the group renamed itself the Data Base Task Group
Data Base Task Group
The Data Base Task Group was a working group founded in 1965 by the Cobol Committee, formerly Programming Language Committee, of the Conference of Data Systems Language .In April 1971, the DBTG published a report containing specifications of a Data Manipulation...
, and its first report in January 1968 was entitled COBOL extensions to handle data bases.
In October 1969 the DBTG published its first language specifications for the network database model
Network model
The network model is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema, viewed as a graph in which object types are nodes and relationship types are arcs, is not restricted to being a hierarchy or lattice.The...
which became generally known as the Codasyl Data Model. This specification in fact defined several separate languages: a data definition language
Data Definition Language
A data definition language or data description language is a syntax similar to a computer programming language for defining data structures, especially database schemas.-History:...
(DDL) to define the schema
Logical schema
A Logical Schema is a data model of a specific problem domain expressed in terms of a particular data management technology. Without being specific to a particular database management product, it is in terms of either relational tables and columns, object-oriented classes, or XML tags...
of the database, another DDL to create one or more subschemas defining application views of the database; and a data manipulation language
Data Manipulation Language
A data manipulation language is a family of syntax elements similar to a computer programming language used for inserting, deleting and updating data in a database...
(DML) defining verbs for embedding in the COBOL programming language to request and update data in the database. Although the work was focused on COBOL, the idea of a host-language independent database was starting to emerge, prompted by IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
's advocacy of PL/I
PL/I
PL/I is a procedural, imperative computer programming language designed for scientific, engineering, business and systems programming applications...
as a COBOL replacement.
In 1971, largely in response to the need for programming language independence, the work was reorganized: development of the Data Description Language was continued by the Data Description Language Committee, while the COBOL DML was taken over by the COBOL
language committee. With hindsight, this split had unfortunate consequences. The two groups never quite managed to synchronize their specifications, leaving vendors to patch up the differences. The inevitable consequence was a lack of interoperability among implementations.
A number of vendors implemented database products conforming (roughly) to the DBTG specifications: the most well-known implementations were Honeywell
Honeywell
Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
's Integrated Data Store (IDS/2), Cullinet's Integrated Database Management System IDMS
IDMS
IDMS is primarily a network database management system for mainframes. It was first developed at B.F. Goodrich and later marketed by Cullinane Database Systems...
, Univac
UNIVAC
UNIVAC is the name of a business unit and division of the Remington Rand company formed by the 1950 purchase of the Eckert-Mauchly Computer Corporation, founded four years earlier by ENIAC inventors J. Presper Eckert and John Mauchly, and the associated line of computers which continues to this day...
's DMS-1100, and Digital Equipment Corporation's
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
DBMS32. Cullinet
Cullinet
Cullinet was a software company whose products included the database management system IDMS and the integrated software package Goldengate. In 1989, the company was bought by Computer Associates...
, originally known as Cullinane Database Systems, obtained the technology from B.F. Goodrich. Cullinet was eventually sold to Computer Associates, which as of 2007 still sells and supports a version of IDMS.
ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
and ISO adopted the Codasyl database specifications under the name Network Database Language (NDL), with work taking place within the same working group (X3H2) as SQL
SQL
SQL is a programming language designed for managing data in relational database management systems ....
standardization. An ISO standard for NDL was ratified as ISO 8907:1987, but it never had any practical effect on implementations, and was formally withdrawn in 1998.
Some of the CODASYL committees continue their work today, but CODASYL itself no longer exists. The records of CODASYL were donated to the Charles Babbage Institute
Charles Babbage Institute
The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
and a catalog may be found at their website.
Interest in CODASYL gradually faded due to growing interest in relational database
Relational database
A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
s beginning in the early 1980s.
Further reading
- The Codasyl Approach to Data Base Management. T. William OlleT. William OlleT. William Olle is a British computer scientist and consultant, and President of T. William Olle Associates, England.- Biography :Bill Olle received a M.Sc. degree in 1954 and a Ph.D...
. Wiley, 1978. ISBN 0-471-99579-7. - The Codasyl Model. J. S. Knowles and D. M. R. Bell, in Databases - Role and Structure, ed. P. M. Stocker, P. M. D. Gray, and M. P. Atkinson, CUP, 1984. ISBN 0-521-25430-2
External links
- Conference on Data Systems Languages Records, 1959-1987 {CODASYL}. Charles Babbage InstituteCharles Babbage InstituteThe Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
, University of Minnesota. CODASYL was a volunteer organization consisting of individuals from industry and government involved in data-processing activity. The organization was formed in 1959 to guide the development of a standard programming language, which led to the development of COBOLCOBOLCOBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
. Collection contains minutes, correspondence, reports, documentation for COBOL, Nice Standard Control Language (NICOLA), the Journal of Development, and other publications from several CODASYL committees and task groups. - Conference on Data Systems Languages {CODASYL} Survey Report, 1968. "The CODASYL Systems Committee 1968 Survey of Data Base Systems" lists several dozen database systems surveyed by the group that created the CODASYL database standard.
- American National Standards Institute. X3H2 records, 1978-1995. Charles Babbage InstituteCharles Babbage InstituteThe Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
, University of Minnesota. The ANSI X3H2 Committee, formed May 1978, was originally charged with creating a standard for the CODASYL network data model. The resulting NDL (network database language) standard was finished in 1982. The committee work on standardizing the relational data model resulted in the SQLSQLSQL is a programming language designed for managing data in relational database management systems ....
(structured query language) standard in 1984.