Better to insert needed variables into apache(!) (or your webserver - respectively) start script.
For example on UNIX systems /etc/init.d/apache would contain following lines before anything else:
#!/bin/bash
if [ -f ~oracle/.profile ]; then
source ~oracle/.profile
fi
The ~oracle/.profile has the appropiate settings to start an Oracle database so it is always up-to-date for PHP, too. (If settings are changed, don't forget to restart your webserver.) This way you just no need to worry what to include or define for PHP.
