Charles William Bachman

By creating the Integrated Data Store (IDS), and advocating forcefully for the concepts behind it, Charles W. Bachman was uniquely influential in establishing the concept of the database management system. During a long and varied career he ran a chemical plant, created cost capital accounting systems, headed an early data processing group, pioneered the application of computers to manufacturing control, led efforts to standardize database and computer communication concepts, won the highest honor in computer science and founded a publicly traded company.

Bachman told me [7] that when he thought about career options as a boy, “I was never interested in anything else. I was always going to be an engineer.” The Second World War temporarily intervened, but in 1950 his dream came true when engineering degrees from Michigan State and the University of Pennsylvania earned him a job with Dow Chemical. An interest in management and cost accounting methods exposed him to punched card machines, and in 1957 he became the founding head of Dow’s corporate data processing department. His work there, and his exposure to other computer center leaders through IBM’s SHARE user group, changed the course of his career.

Business problems led Dow to cancel its computer order prior to delivery. Frustrated, Bachman left Dow in 1960 to work for General Electric, then the textbook example of a well-managed, diversified technology company. He was part of a team responsible for experimenting with new approaches such as operations research, simulation, forecasting, and automation, for possible application across the firm’s many different business units. During the 1950s hundreds of American businesses had rushed to order computers. There was a lot of hype about potential benefits, but getting the machines to do anything useful was much harder than expected. They often ended up being used only to automate narrow clerical tasks like payroll or billing. By 1960 management experts realized that to justify the huge personnel and hardware costs of computerization, companies would need to use computers to tie together business processes such as sales, accounting, and inventory so that managers would have access to integrated, up-to-date information. This was the great dream of corporate computing in the 1960s.

Various firms tried to build such “totally integrated management information systems”, but the hardware and software of the era made that difficult. Each business process ran separately, with its own data files stored on magnetic tape. A small change to one program might mean rewriting related programs across the company. But business needs change constantly, so integration never got very far.

At General Electric Bachman was working on just such as “integrated systems” project, and produced the Manufacturing Information and Control System (MIACS) for a GE manufacturing plant in Philadelphia. Using one of the first available disk drives, his team solved the fundamental problems that defeated so many others.

The crucial invention, operational by 1963, was Bachman’s Integrated Data Store or IDS. IDS maintained a single set of shared files on disk, together with the tools to structure and maintain them. Programs responsible for particular tasks, such as billing or inventory updates, retrieved and updated these files by sending requests to IDS. IDS provided application programmers with a set of powerful commands to manipulate data, an early expression of what would soon be called a Data Manipulation Language.

This made programmers much more productive, because they did not have to grapple with the daunting complexity of working with the “random access” disk storage devices. It also meant that the files could be restructured, moved or expanded without rewriting all the programs that accessed them. IDS maintained a separate data dictionary, tracking information on the different kinds of records in the system and their relationships—for example between customers and the orders they had placed. This was a crucial step towards the integration of different kinds of data, which in turn was vital to the integration of business processes and the establishment of the computer as a managerial tool. Only the boldness of Bachman’s IDS design, and the remarkable efficiency with which he squeezed IDS and the MIACS applications into a computer with the equivalent of 40 Kbytes of memory, made this possible. This tight coupling meant that IDS and the Problem Controller, a transaction scheduling system produced by the same team as an application of IDS, almost entirely replaced General Electric’s rudimentary system software. It was years before any other program matched the power and flexibility of IDS.

By the end of the 1960s the “data base management system,” as programs such as IDS were being called, was one of the most important areas of business computing research and development. When the packaged mainframe software industry boomed during the 1970s, data base management systems were its most important product category. Bachman played an important role in this process, as an early chair and active member of the Database Task Group established by the computer trade association CODASYL (best known as the creator of the COBOL language for business programming) to standardize concepts, terminology and technologies in this area. His design for IDS, and formulation of the underlying concept of the network data model, were the most important influences on the group’s final work.

In 1973 Bachman became the eighth person to win the ACM Turing Award. At that time computer science was a young discipline, and its leaders were struggling to establish it as a respectable academic field with its own areas of theory, rather than as just a technical tool needed to support the work of real scientists such as physicists. So the awards tended to go to brilliant theorists working in prestigious universities. Bachman was the first Turing Award winner without a Ph.D., the first to be trained in engineering rather than science, the first to win for the application of computers to business administration, the first to win for a specific piece of software, and the first who would spend his whole career in industry. Bachman does not believe the award had much impact on his subsequent career progress, although it caused him to develop an interest in Alan Turing’s life and even to visit Sara Turing, Alan Turing’s elderly mother, then in an English nursing home.

His award acceptance lecture, “The Programmer as Navigator,” was an influential declaration of a new world in which complex data structures provided the framework for corporate computing systems, around whose topographies individual application programs would navigate. The award cemented Bachman’s position within the industry as a leading expert on Database Management Systems (DBMS) and the most respected advocate for the network data model and the systems influenced by the CODASYL approach that were rapidly gaining market share in the mainframe world during the mid-1970s.

As such, he stood in opposition to the ideas of Edgar F. (“Ted”) Codd, a mathematically inclined IBM research scientist whose relational model for database manipulation had attracted a growing band of supporters and was beginning to legitimize database systems as a theoretically respectable research field within computer science. A debate between the two and their supporters, held at an ACM workshop in 1974, is remembered among database researchers as a milestone in the development of their field. Bachman stood for engineering pragmatism and proven high performance technology, while Codd personified scientific rigor and elegant but unproven theory. Their debate was inconclusive, which was perhaps inevitable given that no practical relational systems had yet been produced.

Bachman’s influence on today’s data base management systems is unmistakable, even though data base management systems based on Codd’s relational approach, such as Oracle, DB2, and SQL Server, had eclipsed CODASYL systems by the end of the 1990s. Modern relational systems continue to follow the basic template for the data base management system invented by Bachman and his colleagues in CODASYL: a complex piece of software managing data storage, enforcing access restrictions, providing interfaces for both application programs and ad-hoc queries, and providing different views on the same data to different users. Although the rigid connections between different kinds of records that Bachman favored are not part of the relational model itself, pragmatism has pushed modern systems to support them in the form of referential integrity constraints.

Today’s database designers rely on graphical tools to depict the relationships between different tables as a web of connections. These “data structure diagrams” are the direct descendants of a technique Bachman devised [3] to illustrate the complex data structures required for the adaptive manufacturing control logic of MIACS.

Bachman helped guide two highly influential committees during the 1970s. The Study Group – Database Systems was set up in 1972 by the Systems Planning and Resources Committee (SPARC) of the American National Standards Institute (ANSI). Its distinction between conceptual, internal, and external schemas was widely adopted. As chair of the Open Systems Interconnection (OSI) subcommittee of the International Organization for Standardization (ISO) from 1978 to 1982, Bachman helped to formulate the seven layer model of computer communications that has provided the basic framework for discussion of network protocols ever since.

In 1983 Bachman founded his own company, Bachman Information Systems. It followed the classic path of a technology startup, winning funding from leading venture capital firms and making an initial public offering. Its products served the corporate market for data modeling and software engineering. He retired in 1996, but remained active as a consultant specializing in the design of database schemas.

Through all of this he retained an engineer’s zest for the elegant solution of difficult problems, and faith in the power of careful analysis and a systems approach to make the world a better place. As he wrote in a note at the end of our oral history transcript, “My work has been my play.”[7]

Author: Thomas Haigh