file based pref & addr list store?

[David Benjamin]

Has anybody implemented code to store preferences, and perhaps
address lists on simple flat files, rather than SQL databases or LDAP?
Something that, oh say, might be called:

../horde/lib/Prefs/DBM.php
../horde/turba/lib/Driver/DBM.php

or maybe even more simply

../horde/lib/Prefs/FILE.php
../horde/turba/lib/Driver/FILE.php

I recently added support for preference and address list storage
on our IMP installation (versions below).  Everyone was initially
impressed with the spiffy functionality, but now they are dismayed
because:
 - the login time has slowed down significantly
 - the server frequently "wedges" or spews Oracle errors
   which requires an entire server restart, always at bad times.

I'm pretty sure the Oracle errors are a problem with our particular
installation of PHP or Oracle, or both.

But since our user base is <20 people, using Oracle to store
preferences and address lists is tremendous overkill.
Something file based would easily be quicker and a bit more
resilient.

So the first step is to go fishing.  Anyone implemented something
similar?  Anybody think this is a tremendously stupid thing to do?

My apologies if this has come up before.  I try to keep up with
the list, but...

versions:
IMP - cvs head version (ok, maybe two weeks old)
HORDE - cvs head version (ok, maybe two weeks old)
PHP - 4.0.4
APACHE - 1.3.14
MOD_SSL - 2.7.1
ORACLE - 8.1.6