My test/dev env is located on my local desktop. When I want to add some new features to the web site that is already in production - I develop and add new modules on my dev env. Then I use MySQL DB Dump for easy and fast upgrading my new features to the production server.

Steps are:
1. login as administrator on my dev box, goto the admin section of MySQL DB Dump and select one of three options(full database dump, update database dump, update database dump no content) and press submit - as a result SQL file of the tables (structure and data) is stored in the drupal root directory.

2. Then I perform svn commit - I commit all changed files and update_database_dump.sql as well.

3. I go to my server account using ssh and perform svn update.

4. I run special update_database_dump.sh file which logins into mysql and runs update_database_dump.sql - now I check by url that everything is ok.

Here is the link to the CVS where you can download it:
http://code.google.com/p/drupalmysqldumpdb/