Update 4GLs

By Fred Hapgood, CIO |  Development

IN JANUARY 1990

, CIO ran a double article weighing the value of the so-called "fourth generation languages" or 4GLs. These were and are special-purpose application builders customized to specific application domains, such as generating business reports. They are contrasted to general purpose languages (GPLs) or "3GLs," like Cobol or Fortran or C, with which a skilled programmer can build almost anything.

These articles were not, as is sometimes the case, introducing a radical innovation that was shaking up the IT landscape. 4GLs had been on the market, competing with the various 3GLs, since the 1970s. Their selling point was simplicity. 4GL functions were expressed in ordinary English and linked together with everyday syntax. (One offhand definition of 4GLs is "a language that can be learned in two days.") They achieved this simplicity by reducing the most common operations to single commands. A typical 4GL instruction might read: "Extract all customers where 'previous purchases' total more than $5,000." The same statement written in Cobol would run to the end of this article and beyond.

Since each statement taken alone was more powerful than an average statement in a GPL, 4GL programs were shorter and therefore easier to understand and maintain. Thus even those skilled in GPLs might choose to work with a 4GL because at least in theory they could do the same work with fewer statements. According to Gerald Cohen, CEO and founder of Information Builders in New York City, which introduced and still sells one of the very first 4GLs (Focus), "3GLs told the system how to do the application; 4GLs told it what to do."

Nonetheless, the CIO pieces did not add up to an enthusiastic endorsement of the technology. Since each command was like a little program that had to be separately executed, 4GLs were slow. They cost money, whereas most 3GLs came free with the hardware. Most important, 4GLs worked well only for their own problem domain. If any aspect of your project called for a function unanticipated by 4GL's designers, you were back paging through the manual of Cobol commands. An IT worker might as easily decide to stick with his 3GL as take a flyer with one of the new languages -- and many did. "4GLs were like houseboats," Jay Valentine, once a 4GL sales rep (and now CEO of InfoGlide in Austin, Texas), remembers today. "Not very good houses; not very good boats." The article reflected that ambivalence.

In the early '90s, 4GLs found a new opportunity and identity. By their nature the programs focus on the most burdensome task faced by IT personnel at a given moment. In the 1970s and '80s, that task had been writing programs that supported business reporting, that is, routines that pulled data out of a large, complex database running on a mainframe, processed it, configured it to the requirements of a given form and mapped it onto a screen presentation.

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