Oracle Newbie

Hello everyone, I was wondering if anybody would like to share real world experiences in development and deployment of oracle and php. I'm extremely new to oracle & am in the early process of starting to map out a redesign & conversion of a site from postgres to oracle. I am trying to get as much background oracle information as possible. I've read the manual about the php oracle 8i function calls & have done some other web reading. I would appreciate any kind of thoughts in regards to challenges that people have faced with oracle & php.. My other question is will the php oracle 8i calls work with the oracle 9i. Looks like 9i has some cool features, and would like to take advantage of them w/ our java components. We are using php & apache & are using java in the background application processes and other non-web server stuff. FYI, we are also currently using linux. I am trying to get as much info since oracle is a huge beast, and want to do it right the first time around... so Thanks in Advance! Chris