Example DB maintenance scripts anyone?

Hi all I am looking for a few example scripts for ongoing maintenance of a database. The particular problems which we will need to solve include: - adding new tables - adding columns to tables with data in them and setting default values in the new columns Other related bits and pieces as we support our system over the next few months and introduce new functions etc. The basic stuff is all pretty easy with straight forward SQL, the problem comes when trying to put some decent error handling around it, and e.g. detect that a change has already been done and not try again. Is Perl the best tool for this? Any other thoughts? How easy is the PerlDB interface to pick up and use? (By the way this is on HPUX10.20 and currently with Informix 7.24) Robert