direct access to file uploads

I am new to PHP and am trying to get access to files that are uploaded. I have RTFM ;-) and have noticed that PHP writes the file to disk in a temporary location and provides a method/class with all of the information needed to access it. I am loading (PDF's) into a binary field in mySQL and find it rather inefficient to have the file written to disk, and then have it read off and then written back into the db which is ultimately written to disk. Is there a way I can get direct access to the file as it comes in. I noticed a user comment on predefined vars page mentioned $RAW_POST_DATA (or something like that) but no info on how to address it. Is that my answer and what do I do from there? It also seems to be depricated and I do not want to use something that will disappear soon. Thanks in advance, Tom