Re: Online 5.x -> 7.x Upgrade with 4GL Relay Modul

Dieter Winkler wrote: > > Does anyone have experience with the usage of the relay modul? > problems, performance ... > > email: baumschlager@pfeiffer.co.at ESQL/C and 4GL programs compiled under 5.xx and run under the relay module (versions after 7.13 only, earlier versions were VERY buggy) tend to run faster than they did against the 5.xx database server but slower than a native 7.xx executable. I have found that a better upgrade method, however, is to compile everything with the 7.xx compilers, install a 7.xx runtime (or server) environment, point INFORMIXSERVER at the 5.xx engine, and run and debug the 7.xx executables first. Why? Several reasons: 1) When the 7.xx engine is finally brought up you have tested, debugged, native applications ready to run. 2) Once you have verified that compiling under 7.xx has not broken anything (and it rarely does, BTW) you have the luxury of recoding to take advantage of ESQL/C 7.xx features (such as multiple connections and threaded application support to name just two) without the pressure of getting rid of the 5.xx executables ASAP. 3) 7.xx executables run faster against a 5.xx engine than 5.xx executables do, especially if you can take advantage of multiple connections to reduce overhead and/or multiple threads to take advantage of SMP hardware if available. 4) When you do bring up the 7.xx engine your users and management will see the full impact of the upgrade all at once instead of a small improvement from the new engine running the old apps followed weeks later by the new apps coming on-line. 5) If there ARE bugs in the converted 7.xx executables you can quickly rollback to the 7.xx executables compiled from the 5.xx source or even to the old 5.xx executables confident that everything will still work as it always has. Art S. Kagel