small, fast and cross-platform flat-file database for python

[mir nazim]

hi.
i want to know if there is any flat-file relational database system
available for python.
i require it in a project. it should have following capabilities:

1. should be small and compact on system requirments.
2. should be roubust and fast.
3. must be able to handle a bit large tables( upto 5000 rows)
4. should be available for both linux and ms windows 9x/xp/2000
platforms.
5. it will be nice if it supports sql-92.

hopping to find some real good help soon 
bye.
blesess-n-luck