CODASYL

CODASYL (Conference/Committee on Data Systems Languages) 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 the programming language COBOL, the CODASYL Data Model, and other technical 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.

CODASYL is remembered almost entirely for two activities: its work on the development of the COBOL 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.

History

In the late 1950s, computer users and manufacturers were becoming concerned about the rising cost of programming. A 1959 survey had found that in any data processing installation, the programming cost US$800,000 on average and that translating programs to run on new hardware would cost US$600,000. At a time when new programming languages were proliferating, the same survey suggested that if a common business-oriented language were used, conversion would be far cheaper and faster.Template:Sfn

On 8 April 1959, Mary K. Hawes, a computer scientist at Burroughs Corporation, called a meeting of representatives from academia, computer users, and manufacturers at the University of Pennsylvania to organize a formal meeting on common business languages.<ref>Template:Cite journal</ref> Representatives included Grace Hopper (inventor of the English-like data processing language FLOW-MATIC), Jean Sammet, and Saul Gorn.Template:SfnTemplate:Sfn

At the April meeting, the group asked the Department of Defense (DoD) to sponsor an effort to create a common business language. The delegation impressed Charles A. Phillips, director of the Data System Research Staff at the DoD,<ref name = "Flahive, Texas Public Radio, 2019" >Template:Cite web</ref> who thought that they "thoroughly understood" the DoD's problems. The DoD operated 225 computers, had 175 more on order, and had spent over $200 million on implementing programs to run on them. Portable programs would save time, reduce costs, and ease modernization.Template:Sfn

Charles Phillips agreed to sponsor the meeting, and tasked the delegation with drafting the agenda.Template:Sfn

COBOL

On 28 and 29 May 1959, a meeting was held at the Pentagon to discuss the creation of a common programming language for business (exactly one year after the Zürich ALGOL 58 meeting). It was attended by 41 people and was chaired by Phillips.<ref>Template:Cite journal</ref> The Department of Defense was concerned about whether it could run the same data processing programs on different computers. FORTRAN, the only mainstream language at the time, lacked the features needed to write such programs.Template:Sfn

Representatives enthusiastically described a language that could work in a wide variety of environments, from banking and insurance to utilities and inventory control. They agreed unanimously that more people should be able to program, and that the new language should not be restricted by the limitations of contemporary technology. A majority agreed that the language should make maximal use of English, be capable of change, be machine-independent, and be easy to use, even at the expense of power.Template:Sfn

The meeting resulted in the creation of a steering committee and short, intermediate, and long-range committees. The short-range committee was given until September (three months) to produce specifications for an interim language, which would then be improved upon by the other committees.Template:SfnTemplate:Sfn Their official mission, however, was to identify the strengths and weaknesses of existing programming languages; it did not explicitly direct them to create a new language.Template:Sfn

The deadline was met with disbelief by the short-range committee.Template:Sfn One member, Betty Holberton, described the three-month deadline as "gross optimism" and doubted that the language really would be a stopgap.Template:Sfn The steering committee met on 4 June and agreed to name the entire activity the Committee on Data Systems Languages, or CODASYL, and to form an executive committee.Template:Sfn

The short-range committee members represented six computer manufacturers and three government agencies. The computer manufacturers were Burroughs Corporation, IBM, Minneapolis-Honeywell (Honeywell Labs), RCA, Sperry Rand, and Sylvania Electric Products. The government agencies were the U.S. Air Force, the Navy's David Taylor Model Basin, and the National Bureau of Standards (now the National Institute of Standards and Technology).Template:Sfn The committee was chaired by Joseph Wegstein of the U.S. National Bureau of Standards. Work began by investigating data descriptions, statements, existing applications, and user experiences.Template:Sfn

The committee mainly examined the FLOW-MATIC, AIMACO, and COMTRAN programming languages.Template:SfnTemplate:Sfn The FLOW-MATIC language was particularly influential because it had been implemented and because AIMACO was a derivative of it with only minor changes.Template:Sfn<ref name=cisn>Template:Cite journal</ref> FLOW-MATIC's inventor, Grace Hopper, also served as a technical adviser to the committee.Template:Sfn FLOW-MATIC's major contributions to COBOL were long variable names, English words for commands, and the separation of data descriptions and instructions.Template:Sfn Hopper is sometimes called "the mother of COBOL" or "the grandmother of COBOL",<ref>Template:Cite magazine</ref><ref>Template:Cite journal</ref><ref>Template:Cite book</ref> although Jean Sammet, a lead designer of COBOL, said Hopper "was not the mother, creator, or developer of Cobol."<ref>Template:Cite news</ref><ref name="creators">Template:Cite journal</ref>

IBM's COMTRAN language, invented by Bob Bemer, was regarded as a competitor to FLOW-MATICTemplate:SfnTemplate:Sfn by a short-range committee made up of colleagues of Grace Hopper.Template:Sfn Some of its features were not incorporated into COBOL so that it would not look like IBM had dominated the design process,Template:Sfn and Jean Sammet said in 1981 that there had been a "strong anti-IBM bias" from some committee members (herself included).Template:Sfn In one case, after Roy Goldfinger, author of the COMTRAN manual and intermediate-range committee member, attended a subcommittee meeting to support his language and encourage the use of algebraic expressions, Grace Hopper sent a memo to the short-range committee reiterating Sperry Rand's efforts to create a language based on English.Template:Sfn

In 1980, Grace Hopper commented that "COBOL 60 is 95% FLOW-MATIC" and that COMTRAN had had an "extremely small" influence. Furthermore, she said that she would claim that work was influenced by both FLOW-MATIC and COMTRAN only to "keep other people happy [so they] wouldn't try to knock us out.".<ref name="Hopper Oral History">Template:Cite web</ref>

Features from COMTRAN incorporated into COBOL included formulas,Template:Sfn the [[#PICTURE clause|Template:Code clause]],Template:Sfn an improved IF statement which obviated the need for GO TOs, and a more robust file management system.Template:Sfn

The usefulness of the committee's work was a subject of great debate. While some members thought the language had too many compromises and was the result of design by committee, others felt it was better than the three languages examined. Some felt the language was too complex; others, too simple.Template:Sfn

Controversial features included those some considered useless or too advanced for data processing users. Such features included Boolean expressions, formulas, and table Template:Dfn (indices).Template:SfnTemplate:Sfn Another point of controversy was whether to make keywords context-sensitive and the effect that would have on readability.Template:Sfn Although context-sensitive keywords were rejected, the approach was later used in PL/I and partially in COBOL from 2002.Template:Sfn Little consideration was given to interactivity, interaction with operating systems (few existed at that time), and functions (thought of as purely mathematical and of no use in data processing).Template:SfnTemplate:Sfn

The specifications were presented to the executive committee on 4 September. They fell short of expectations: Joseph Wegstein noted that "it contains rough spots and requires some additions," and Bob Bemer later described them as a "hodgepodge." The committee was given until December to improve it.Template:Sfn

At a mid-September meeting, the committee discussed the new language's name. Suggestions included "BUSY" (Business System), "INFOSYL" (Information System Language), and "COCOSYL" (Common Computer Systems Language).Template:Sfn It is unclear who coined the name "COBOL",Template:SfnTemplate:Sfn although Bob Bemer later claimed it had been his suggestion.<ref>Template:Cite news</ref><ref>Template:Cite web</ref><ref>Template:Cite web</ref>

In October, the intermediate-range committee received copies of the FACT language specification created by Roy Nutt. Its features impressed the committee so much that they passed a resolution to base COBOL on it.Template:Sfn

This was a blow to the short-range committee, who had made good progress on the specification. Despite being technically superior, FACT had not been created with portability in mind or through manufacturer and user consensus. It also lacked a demonstrable implementation,Template:Sfn allowing supporters of a FLOW-MATIC-based COBOL to overturn the resolution. RCA representative Howard Bromberg also blocked FACT, so that RCA's work on a COBOL implementation would not go to waste.Template:Sfn

It soon became apparent that the committee was too large to make any further progress quickly. A frustrated Howard Bromberg bought a $15 tombstone (in 1959; equivalent to roughly $Template:Inflation now)Template:Inflation-fn with "COBOL" engraved on it and sent it to Charles Phillips to demonstrate his displeasure.Template:Efn<ref name="Tombstone story">Template:Cite journal</ref>Template:Sfn

A subcommittee was formed to analyze existing languages and was made up of six individuals:Template:SfnTemplate:Sfn

• William Selden and Gertrude Tierney of IBM,
• Howard Bromberg and Howard Discount of RCA,
• Vernon Reeves and Jean E. Sammet of Sylvania Electric Products.

The subcommittee did most of the work creating the specification, leaving the short-range committee to review and modify their work before producing the finished specification.Template:Sfn

The specifications were approved by the executive committee on 8 January 1960, and sent to the government printing office, which printed them as COBOL 60. The language's stated objectives were to allow efficient, portable programs to be easily written, to allow users to move to new systems with minimal effort and cost, and to be suitable for inexperienced programmers.Template:Sfn

The CODASYL Executive Committee later created the COBOL Maintenance Committee to answer questions from users and vendors and to improve and expand the specifications.Template:Sfn

During 1960, the list of manufacturers planning to build COBOL compilers grew. By September, five more manufacturers had joined CODASYL (Bendix, Control Data Corporation, General Electric (GE), National Cash Register, and Philco), and all represented manufacturers had announced COBOL compilers. GE and IBM planned to integrate COBOL into their own languages, GECOM and COMTRAN, respectively. In contrast, International Computers and Tabulators planned to replace their language, CODEL, with COBOL.Template:Sfn

Meanwhile, RCA and Sperry Rand worked on creating COBOL compilers. The first COBOL program ran on 17 August on an RCA 501.Template:Sfn On 6 and 7 December, the same COBOL program (albeit with minor changes) ran on an RCA computer and a Remington-Rand Univac computer, demonstrating that compatibility could be achieved.<ref name="Williams12">Template:Cite book</ref>

The relative influence of the languages that were used is still indicated in the recommended advisory printed in all COBOL reference manuals: Template:Blockquote

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 (DBTG), and its first report in January 1968 was entitled COBOL extensions to handle data bases.

File:CodasylB.png

The "set", the basic structure of the CODASYL database model. A set consists of one owner record and n member records (these are labeled as "parent" and "child" in the diagram, but the CODASYL terminology is "owner" and "member"). In the above example, we were looking at a basic set which embodies a 1:N (Owner:Member) relationship.<ref>Template:Cite book</ref>

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 best-known implementations were Honeywell's—originally General Electric's—Integrated Data Store (IDS/2), HP's IMAGE, Cullinet's Integrated Database Management System IDMS, ICL's 2900 IDMS (derived from Cullinet's product), Univac's DMS-1100, and Digital Equipment Corporation's DBMS for VMS (later known as Oracle Codasyl DBMS). 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,<ref>Template:Cite web</ref> but, as it never had any practical effect on implementations, it 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.<ref>See a finding guide to Conference on Data Systems Languages Records, 1959-1987. Charles Babbage Institute, University of Minnesota</ref> CBI also hold the archival records for American National Standards Institute X3H2 records.

Interest in CODASYL gradually faded due to growing interest in relational databases beginning in the early 1980s.

See also

• Navigational database
• T. William Olle

References

Sources

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Further reading

• The Codasyl Approach to Data Base Management. T. William Olle. Wiley, 1978. Template:ISBN.
• 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. Template:ISBN
• Joseph M. Hellerstein and Michael Stonebraker "Readings in Database Systems", The MIT Press 2005 Page 8, Template:ISBN, Library of Congress Control Number: 2004113624,

External links

• Conference on Data Systems Languages Records, 1959-1987 {CODASYL}. Charles Babbage Institute, 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 COBOL. 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 Institute, 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 SQL (structured query language) standard in 1984.