Re: Rapid Development system

72274.115@compuserve.com wrote: > > I'm looking for opinions on the Rapid Development system. Is the > resulting object any faster, better, or worse, than the c4gl output? The resulting RDS executable is generally slower than compiled 4GL (C4GL) except for database operations which do not suffer appreciably. The penalty depends on how much of the program is devoted to calculation and how much to database operations and screen operations. For heavy duty screen functions the delays are not noticeable as long as major calculations are not required in AFTER FIELD type clauses. The normal penalty for batch programs is about 15% but can be as much as 25% for heavy compute bound programs. This can be reduced significantly by writing calculation modules in "C" and linking them into the pcode runner for RDS. This is a good technique to reduce the overhead in C4GL programs also which can be as much as 15% slower than the equivalent "C" function if compute bound. So if you make a discipline of writing compute modules in "C" and linking a custom runner for your RDS applications these same functions can be placed into a library or shared library for C4GL compiled programs and migrating from RDS to C4GL still gains you noticeable improvement. The memory footprint for C4Gl is less than for RDS executables if more than a few applications are running on the same machine and even less still if more than a few users are running the same executable on one machine, especially if you put common code in shared libraries. For a single copy of a single executable RDS uses less memory. BTW, little known fact, C4GL compiled 4GL functions which are commonly shared can also be linked into an RDS runner! Art S. Kagel