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Shopping for a Fourth Generation Language

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Shopping for a Fourth Generation Language If you're in the market for a 4GL, you'd better be in the mood to answer 10 basic questions. SHOPPING FOR A FOURTH GENERATION LANGUAGE by George Schussel question is, do you like the syntax? Actual- ty in decision support and information cen- ly, a broad range of syntax is available for ter applications. Languages like Focus are Fourth generation languages are like a the different ~GLS.Some products like Fo- therefore more effective in nonprocedural good set of tools-when you need them cus, Natural, and Mantis, which are very applications, while languages like Ideal and they come in handy. Today's 4GL software language-oriented, have instructions that Natural, which have procedural features, provides significantly different solutions are written in code or English language-like offer enough detail cpntrol to solve almost for improving productivity compared with statements. Support for both procedural any problem that can be handled by COBOL. third generation COBOL and FORTRAN. The and nonprocedural constructs also exists. semantic and syntactical differences among People who have experience in program- RUN-TIME Next, ~GLbuyers should ~GLSare also far greater than the differ- ming will be very comfortable with lan- VERSION ask, is a run-time version ences between FORTRAN and COBOL. And guage-based formats. of the system required? although 4GLs are similar in some ways- In contrast, other systems do much NEEDED? The best-known 4GLs are most interface to one or more database of their work through function generation. proprieta~ylanguages like Focus, Natural, management systems, provide query facili- Ideal from Applied Data Research (Prince- Mantis, ADS/O, and Sperry's Mapper, ties and report writers, and support screen ton, N.J.), Application Factory from Cor- which combine some interpretive and some painting and some kind of procedural lan- tex Corp. (Wellesley, Mass.), Ally from compiled features. All of these languages guage-proprietary versions vary greatly in Foundation Systems (American Fork, require a run-time version of the vendor's the types of applications and environments Utah), and ADS/O tend to fall into this cate- software. they are best suited for. gory. Much of their functionality comes This is a fine solution if you are us- Some ~GLS,such as Natural from through interactive sessions and dialogs ing a particular brand of hardware for both Software AG (Reston, Va.), Mantis from that are menu driven. These sessions are building and running your applications. Cincom (Cincinnati), and ADS/O from Cul- normally used to specify report formats, But what if you want to build in one envi- linet (Westwood, Mass.), are designed for screens, and data definitions. In addition, ronment and migrate to another or even the professional programmer who builds menu driven front ends have recently been several other environments? In this case, complex systems. Others, such as Focus added to some language-oriented products, you need to look at ~GLenvironments that from Information Builders (New York), such as Focus and Ramis 11. do not require run-time modules. Since Ramis I1 from Martin Marietta Data Sys- Potential ~GLpurchasers should most COBOL systems generation technol- tems (Greenbelt, Md.), and Nomad2 from then ask themselves the second question, ogies-such as Gamma by Tarkenton Soft- D&B Computing Services (Wilton, Conn.), how procedural is the language? If the lan- ware (Atlanta), Transform/~~sfrom are geared more to the information center guage is procedural, as is the case with Transform Logic Corp. (Scottsdale, Ariz.), user. Still other ~GLproducts, such as Pac- assembler or third generation languages and Pacbase-generate structured COBOL base from CGI Systems (Pearl River, N.Y.), like COBOL and FORTRAN, then the user, code and native DBMS calls, they do not re- Telon from Pansophic Systems (Oak through constructs such as IF THEN ELSE, quire the vendor's system at run time. Brook, Ill.), and APS from Sage Systems GO TO, and DO, tells the computer exactly Before deciding on any ~GL,you (Rockville, Md.), generate COBOL and data- how to take each step. If, on the other have to determine who the user is going to base calls. While these COBOL systems gen- hand, the language is nonprocedural, then be. So, question number four is, who is the erators are also aimed at the professional the user tells the computer what to do, not targeted user? Some 4GLs are designed for programmer, they are usually complete how to do it. Typical programming in a people with a programming background. life-cycle management tools with modules nonprocedural language supports various These products generally have more proce- for project planning and control, librarian constructs such as the following: SELECT durally oriented languages. They also usu- functions, and documentation. DATA FROM FILE, PRINT REPORT, and OR- ally have performance features like There are 10 basic questions buyers DER BY EMPLOYEE NUMBER. multithreading capability, which allows should examine in evaluating whether a While procedural languages are transaction processing applications to be particular 4GL product is meant for their needed to build sophisticated, corporate dp built that support up to several hundred si- dp environments and applications. The first systems, they can interfere with productivi- multaneous terminal users. NOVEMBER 1, 1986 99 Most IBM software systems do not support the active dictionary concept. Other ~GLSoffer a friendlier inter- written in these languages-small or large companies that strongly support the active face that is easier for nontechnical types to databases, small or large numbers of trans- dictionary concept. IBM software systems master. These high-productivity, less pro- actions, batch or on-line systems, and logic do not support this active dictionary fea- cedural products are frequently used in in- that runs the gamut from very procedural ture. Neither DB~nor CSP, for example, formation retrieval applications. to not so procedural. support an active dictionary. Most ~GLS After the user is identified, you Other 4GLs, like ADS/O,can be used that are tailored to the information center should ask, what kinds ofprogrammer sup- for a slightly narrower range of applica- support a passive dictionary. These prod- port tools are provided and are they highly tions. The building of batch logic, for in- ucts require the programmer to take proce- interactive? Some ~GLproducts allow inter- stance, requires a separate system. And still dural steps to invoke the dictionary. pretive execution and debugging upon other easy-to-use 4GLs, such as Focus, Ra- completion of each line of code or at the mis 11, and Nomad2, provide more suitable WHICH That brings us to ques- completion of each step of function genera- performance for building departmental, as SUPPO~ tion number eight-is tion. Others require you to complete pro- opposed to corporate, computing systems. your ~GLa language or a gramming tasks and then go into separate The next question that crops up in SYSTEM? life-cycle support system? modules for execution. When an error is evaluating ~GLSis, what support is there for Of course, ~GLSprovide languages and fa- found in the execution module, the task an active dictionary? An active integrated cilities to build applications. A number of must be terminated while the development data dictionary/directory significantly en- ~GLwares have even been enhanced to sup- module is brought back up and changes hances control of a fourth generation soft- port such tasks as system and database de- made. While IBM'S CSP offers debugging ware environment. The active dictionary is sign, table management, librarian trace facilities, it also requires the devel- a software component that stores data defi- functions, project management, and techni- oper to change modules. nitions, edits, and serves as the integrating/ cal and user documentation. The sixth question you should ex- control unit for the entire software environ- Generally, the more support the plore is, how diverse are the applications ment. Generally, the software technologies system provides, the more suitable it is for that can be coded? Some ~GLSsuch as Nat- aimed at the professional programmer level adoption as a complete technology by the ural and Ideal can be used for a broad provide active dictionary products. dp department. If, however, your dp shop range of applications. Almost any 'applica- Cullinet, Cincom, Applied DataRe- already has adequate systems development tion that can be written in COBOL can be search, and Software AG are some of the support and only needs to get certain types of programs operational more quickly, then a full documentation and life-cycle support environment may simply provide too much THE NATIONAL DATABASE AND extra baggage and unnecessary overhead. You should also ask the related 4TH GENERATION LANGUAGE SYMPOSIUM question, how much education and invest- Boston, December 2-5, 1986 ment are needed? It normally takes more education and investment to make a com- The fourth generation of software has become accepted as the best approach plete life-cycle support system productive for developing applications, yet many companies are lagging behind in than it does to get products with less func- switching to a 4th generation language product because they fear purchasing tionality up to snuff. For example, Pacbase, the wrong product for their company. which provides a great deal of support for It is your right as a buyer to expect a system to perform as advertised, but it is development, requires a major initial com- your responsibility to become an EDUCATED buyer. You should know what mitment. Mantis, on the other hand, can be installed and used quickly. you need, why you need it, which systems offer it, and finally, what you can Finally, ~GLsystem shoppers realistically expect from a system once it is in place. By attending the National should ask, what type of integration is sup- Database and 4th Generation Language Symposium you will be able to ported? Usually ~GLproducts are either make the informed purchasing decisions so critical to your company's future.
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