Thanks, this sparked a recollection and I got a solution working that didn't require exec() or messy wrappers. In fact, it is desirable in context of this code to put the "use DBD::Oracle;" in a module, so the exec was questionable for me anyway...

Use a .conf file and ldconfig. RedHat and others support this nowadays. (Google knows more about this than I do, so I leave the research to the reader.) Now on my "standard platforms" I have a .conf file listing the various LD_LIBRARY_PATHs I use, including the standardized path to Oracle client, and did ldconfig to reload that cache, and all is right with the world. No fussing with wrappers or messy execs.

Now if only we could prod Perl to force a reload of that cache (and subsequently its own), we wouldn't have an OS dependency...