Designing database from scratch

[alex@owal.co.uk]

Folks,

I'm designing a database from scratch and want to progress from the "back
of an envelope design". I'm thinking of using SQL Fairy eg


I write an XML description of the SQL Schema

SQL Fairy converts that to

   MySQL SQL Code (typically create statements)

and possibly

   Class::DBI

and definitely

   GraphViz diagrams


(I'll also be writing some Java code to access the database too and
possibly some PHP to if I am unlucky).

What is the "state of the art" for database design in the open source
world? What do you use?

Alex