I think he wants to treat a flat file as a mysql database. If you are
serious about it i would suggest you look up hashing to disk. I dont
know of any ways to treat a flat file like a database in PHP, only perl
with CSV. You would have to create any functionality.

I have only delt with flat files if i know it wont get too long, mainly
because searching is a pain in the butt, ordering helps but not if you
are going to sort by multiple fields.

In order to help out a bit, let us know what you are actually trying to
do, your goal. That would help us get the ball rolling and better help
you out.

Bob