ILE Implementation
It is not the aim of this section to explain the workings of the Integrated Language Environment (ILE), but rather LANSA's implementation of ILE. It is recommended the IBM Manual be reviewed and understood before reading on.
The decision to migrate to the ILE environment should first involve addressing the advantages and disadvantages of ILE. Once the decision is made to migrate to ILE environment and its methodology (i.e.many small, modular programs, call intensive) it becomes uneconomical to revert back.
The ability to run and develop ILE programs is enabled by different system features. To develop ILE applications requires the ILE RPG/400 compiler. The ILE RPG/400 compiler must be purchased separately.
LANSA places all called programs into the default activation group (i.e.*CALLER is used in the ACTGRP() parameter of CRTPGM). In this way ILE programs behave in the same manner as OPM programs.
There is a memorandum from IBM to IBM i ILE RPG/400 customers on the subject of migrating to ILE RPG/400 that should be read. In summary this document mentions that:-
- "The disk storage requirements for ILE/RPG programs have increased to 1.5 to 3 times relative to OPM RPG/400"
- "If you recompile a traditional OPM RPG/400 program with the ILE RPG/400 compiler, you will experience compile-time degradation of greater than 2X the performance compared to OPM RPG/400 compiler."
- Suggestions for the amount of memory needed by the ILE RPG/400 compile process are to "Use 12-16MB to compile medium sized programs" and "Use 20 MB to compile large programs".
Also see