Document information systems

The expansion of personal computer capabilities has enabled the development of programs for storing and retrieving documentary information that take full advantage of professional microcomputers. This has allowed many libraries, documentation centers, and information units in general to mechanize their workflow management and begin creating automated documentary databases.

Here, documentary information is understood as any type of textual information, whether physically structured in the form of monographs, journal articles, dossiers, reports, memoranda, etc., or as descriptions of “objects” that are not documents: medical records, biographies, descriptive information about institutions and monuments, ongoing research, contract specifications, administrative procedures, and so on.

Until 1982, mainly due to the scarcity of specific programs, microcomputers were not yet widely used in documentation centers, libraries, and information services. The few software packages available were designed for 8-bit computers running the CP/M operating system, and only rarely included hard-disk units for large-scale data storage. Starting in 1983, however, with the massive introduction of the IBM PC into the market—and particularly its professional version, the PC/XT equipped with a 10-MB hard disk—the situation changed substantially and the supply of programs specialized in the management of documentary information increased significantly.

As the PC became the standard in the computer market, new programs were developed to exploit its capabilities to the fullest: higher speed, large fixed hard disks, the shift from CP/M to MS-DOS, and the addition of documentary-management features that until then were found only in larger systems. These trends appeared especially in the United States and in certain European countries: the United Kingdom, France, Germany, and the Scandinavian nations. Our country remained largely outside this evolution, and only at the end of 1984 and throughout 1985 did some Spanish firms begin developing and marketing original programs or acquiring the rights to distribute foreign software packages.

The development of “supermicros”—the PC AT and its compatibles—together with local-area network technology and multiuser microcomputers based on MS-DOS or UNIX implementations (XENIX, PC-IX), expanded the field of application of microcomputers in documentary information management from personal, professional, and small-institution contexts to the environments of medium-sized and even large organizations.

Given the wide variety of products available on the market, successful automation requires first taking into account the main types of programs developed for documentary applications:

A) Document management systems
B) Library management systems
C) Gateway programs for communication with large commercial databases
D) Programs for retrieving information from files generated by word-processing software
E) Programs for automating the development of documentary tools

Information retrieval

Once the file has been created and the necessary data entered, it can be used for information retrieval. A real file, to be worth controlling through a computer, should contain at least around one hundred records. Let us define a small file as an example:

Suppose we want to find items measured in kilograms and priced below 50 pesetas. The following two commands are sufficient to solve the problem.
The first command informs the system that the user intends to use the file:

Catálogo

The second command activates the query function and displays on the screen all records referring to items measured in kilograms and priced below 50 pesetas. It is important to note that an ordinary program would have required more than two instructions. The function described and the commands used provide a starting point for some relevant considerations. The various functions a database is capable of performing are activated by the user through one or more commands that begin with an English verb followed by specific elements. The verb generally indicates the function to be activated, while the following elements specify and delimit its meaning. This ensures that each command has a formal structure the user must know in advance in order to execute it correctly. In other words, the user must learn the language required to operate the database.

Conceptually, this is not very different from learning a programming language. However, learning a database language is easier and more motivating for the following reasons:

• The number of commands to learn is smaller than in a programming language; with a limited number of essential commands, significant results can already be achieved.
• There is no need to learn how to structure a program or produce its logical block diagram.

Data Updating and Maintenance

Once a file containing its data has been created, we may wish to modify its structure in some way—either by altering specific characteristics of the data or by adding, deleting, or modifying records in the database. In general, all databases offer functionalities that make their definition and manipulation flexible, although the extent of this flexibility depends largely on the system we use.