The problem is even if you do it that way the linker already has LD_LIBRARY_PATH cached and you can't change it. The linker is started (and caches LD_LIBRARY_PATH) as soon as perl is started. You really need to set LD_LIBRARY_PATH before perl even starts. Other that just setting LD_LIBRARY_PATH in the environment the only solution I came up with was to set the environment, fork, and have the new process do the DB work. But that was kind of hokey and I didn't like spawning the second process to do the work. I tried to look for ways of chainging solaris's linker to not cache LD_LIBRARY_PATH but never got very far.

BTW, LD_LIBRARY_PATH (and any other environmental vars used by the linker) are the only ones you need to worry about. You're OK setting other environmental vars (ORACLE_HOME, TNS_ADMIN, etc...) in your perl script. The problem is strictly related to the behavior of solaris's linker.