When you say "edit routines", do you mean FIELDPROCs, EDITPROCs, and
VALIDPROCs? If so, I'm surprised to see anyone still use those things. I'm
not sure they ever got much use and there is probably even less reason to
use them now that constraints, UDFs, etc. are present and relatively
powerful.

If I remember correctly, the fieldproc/editproc/validproc family all had to
be written in Assembler, making them fairly awkward to maintain, especially
if you didn't have a good Assembler programmer in your shop. That was the
main reason they didn't get a lot of use, at least among the people I knew
who were running DB2. As a result, you probably won't find many people who
know the effect of these procs on DB2 performance; you'll probably have to
set up a bunch of test cases and do your own explains to find out what they
do to index selection.

If that is NOT what you mean by "edit routines", what DO you mean?

Rhino