Re: Diference between 4GL and 4GL-RDS

->From: tkon@leon.nrcps.ariadne-t.gr (Thanassis S. Kontonatsios) ->Subject: Diference between 4GL and 4GL-RDS ->Date: Tue, 31 Aug 1993 15:47:22 GMT ->Reply-To: tkon@leon.nrcps.ariadne-t.gr (Thanassis S. Kontonatsios) ->Organization: Siemens Nixdorf (Greece) -> ->Hi netters ! -> ->Does anyone have the time to explain to me what is the difference [1] ->between 4GL and 4GL-RDS ? -> ->Is it a good idea to use 4GL-RDS in a UNIX environment ? [2] -> ->many thanks, ->tkon Hi, Thanassis, [1] The 4GL product compiles to native machine language, via C. The 4GL-RDS product "compiles" to an intermediate p-code, which is interpreted by the runner. The p-code is *machine independent*; the p-code runner is machine dependent. Both use the same 4GL source language. Both use the same (at least on Sun systems) run time dynamic link libraries. [2] Sure, why not? Some folks say that RDS is slower, because it is interpreted. However, instruction execution/interpretation is not the bottleneck. Database access is normally the bottleneck in an application. In one test that we did, the RDS version of the application consistently ran faster than the compiled-to-native-code version. (My theory, for what it's worth: The RDS runner DBMS accesses could be more optimized because the runner would filter out abnormal conditions. The compiled code had to include more error checking--in loops, etc.--because directly compiled stuff could contain errors that the RDS runner would never commit.) Note that if you run multiple environments, it might be more economical to use RDS. You could develop on one system that has a development license, and then run the p-code on other systems that only have run-time licenses, even if the hardware is not binary compatible. With compiled 4GL, you need a development license for each hardware set. Regards, Alan ___________________________ ______________________| R. Alan Popiel |__________________________ \\ Internet: | Martin Marietta, Tech Ops | / \\ alan@den.mmc.com | P.O. Box 179, M/S 5422 | Std disclaimers apply. / )Voice: | Denver, CO 80201-0179 USA | ( / 303-977-9998 |___________________________| (But you knew that!) \\ /________________________) (____________________________\\