Reports would be generated based on the tables, no different from an Oracle based stack.
RPG code is fairly easy to understand as well. Any experienced auditor or consultant would be abe to understand the routines easily. Maybe more easily than a Perl or C stack.
I'm no fan of AS/400 for many reasons, but complexity is not one of them.
With the fixed formatting and "program cycle", RPG was intended as a sort of skeumorph for technicians who would have been trained to "program" unit record equipment on a wiring diagram. (Contrast the wiring schematic here: http://www.righto.com/2017/04/1950s-tax-preparation-plugboar... with an RPG template here: https://www.richard-banks.org/2014/01/a-little-nostalgia-wit...)
That's an excellent point. I meant free format code
This leads to pearls of wisdom like “An indicator is like an atomic bomb, nice to have but not something you want to use.” And “if you solve the problem with an indicator, then you’ll have two problems.”
These may be carefully engineered to be compatible at many levels, but they are not the same thing, as Oracle might be as it is compiled for its supported platforms.