The server I work on currently runs aix 5.1, 32 bit. The OS and subsequently Perl too is being upgraded to 64 bit. I need to know whether all the Perl modules/libraries have to be recompiled/reinstalled when Perl switches to 64 bit. The modules being used are DBI and a few other custom made bespoke modules. The DBD Oracle module will be changed to 64 bit. So does the DBI module which uses DBD need to be recompiled.
There may be a way to run a 32 bit Perl on a 64 bit AIX, but since you can just recompile and have a much more stable environment I'd strongly recommend doing that. Mixing operating modes is often an invitation to disaster, since you can run into all kinds of problems when you get 95% of your code running, but then have the remainng 5% do "strange things" for ages!