Chapter 2 • Computer Systems 473 GL, the programmer must devise a step-by-step proce-
dure to accomplish the desired result and express this pro-
cedure in the form of 3 GL statements. With a 4 GL, the
computer user merely gives a precise statement of what he
or she wishes to accomplish, not an explanation of how to
do it (as would be done for a procedural language). The 4
GLs generally employ English-like syntax and—because
they are predominantly nonprocedural in nature—the
order in which instructions are given in a 4 GL is usually
unimportant. In addition, 4 GLs do not require the user
to manage memory locations in the program like 3 GLs,
resulting in less complex programs.
The 4 GLs employ very-high-level instructions not
present in 3 GLs, and thus 4 GL programs tend to require
significantly fewer instructions than their 3 GL counterparts.
This in turn means that 4 GL programs are shorter, easier to
write, easier to modify, easier to read and understand, and
less error-prone than 3 GL programs. Fourth generation lan-
guages are sometimes called very-high-level languages in
contrast to the high-level third generation languages.
Some fourth generation languages use an interpreter
to translate the source program into machine language, and
some use a compiler. Please note that the 3 GLs and 4 GLs
are essentially the same from one computer model to the
next, but the translation programs (compilers and inter-
preters) must be specific to the particular computer model.
With these advantages, why aren’t all programs writ-
ten in 4 GLs today? First, many of the 4 GLs are not general-
purpose languages and cannot be used easily for many
types of programs. Second, many programs are not written
in 4 GLs because of concern for efficient use of the
computer resources of the organization. For the most part,
4 GL programs translate into longer machine language
programs that take much longer to execute than the equiv-
alent programs written in a 3 GL. The upshot of these argu-
ments is many one-time programs or infrequently used
programs (such as a decision support system or a special-
ized management report) are written in 4 GLs, while most
production programs (those that will be run every day or
every week) are written in 3 GLs. In the case of infrequent-
ly used programs, human efficiency in writing the program
is more important than computer efficiency in running it;
for production programs, the opposite is often the case.
The roots of fourth generation languages date back to
1967, with the introduction of RAMIS (originally devel-
oped by Mathematica, Inc., and now sold by Computer
Associates as CA Ramis). Another early entry that is still in
use today is FOCUS (from Information Builders). Initially,
these products were primarily available on commercial
time-sharing networks (like Telenet and Tymnet), but direct
sales of the products to customers took off about 1980. By
the mid-1980s, FOCUS was estimated to command about
20 percent of the market, with RAMIS following with
16 percent (Jenkins and Bordoloi, 1986).
In the late 1980s and early 1990s, the 4 GL market
became even more splintered as new versions of the early
4 GLs were rolled out and a wide variety of new products
entered the marketplace. The emphasis of the products
appearing in the 1990s was on portability—the ability of
the 4 GL to work with different hardware platforms, oper-
ating systems, and database management systems and over
different types of networks (Lindholm, 1992). In the late
1990s and early 2000s, the 4 GLs changed again. First,
most 4 GLs added a Web interface so that they could be
used from a PC without requiring any special software on
the PC. Second, and even more important, the focus of
these products shifted to business intelligence (BI),and
the 4 GL label essentially disappeared. Today’s business
intelligence software tools are designed to answer queries
relating to the business by analyzing data (often massive
quantities of data), thereby providing “intelligence” to the
business that will help it become more competitive. Of
course, this focus on business intelligence is not that differ-
ent from the focus of 4 GLs in the past; it really is an evo-
lution, not a drastic change.
Some of the 4 GL products are full-function, general-
purpose languages like CA Ramis and FOCUS and have
the complete functionality necessary to handle any appli-
cation program (although they may be more difficult to use
than 3 GLs for some applications). Thus, they are direct
competitors with the 3 GLs. Other 4 GLs were created to
handle a particular class of applications, such as statistics,
decision support, or financial modeling. For example, SAS
(from SAS Institute) began as a limited-purpose 4 GL
focusing on decision support and modeling. SAS Business
Intelligence has now expanded to an integrated suite of
software for business intelligence in an enterprise, with
extensive capabilities in data access, data management,
data analysis, and data presentation. Among the more pop-
ular business intelligence products today are WebFOCUS
(a Web-based, business-intelligence-oriented version of
FOCUS), IBM Cognos 8 Business Intelligence,
MicroStrategy 9, SAP BusinessObjects (Germany), Oracle
Business Intelligence Enterprise Edition Plus (formerly
Hyperion), and Microsoft SQL Server 2008 Analysis
Services and SQL Server 2008 Reporting Services.
The fourth generation languages are evolving more
rapidly than those in the third generation, particularly with
the addition of easy-to-use business intelligence options
and easy-to-interpret graphical output and colorful dis-
plays. However, the 4 GL label is disappearing in favor of
the business intelligence (BI) tag. Furthermore, with
the increasing capabilities of today’s computers, the lack
of efficiency of execution of 4 GL programs vis-á-vis 3 GL