If you're a module developer working on a module that uses one more tables, you'll probably want to make your module compatible with this one. I've personally found it a really invaluable tool for quickly eliminating the DB structure as the source of issues. The module works really, really simply. It works by taking a snapshot of a valid database and generates a PHP array containing the database table and column info. For testing, it then compares the actual DB structure with the content in that file.
Take a look at the dbi_generate_db_config_file - this generates a PHP file for your tables. What's probably simplest is just to edit the /database_integrity/index.php file and uncomment the lines labeled "module table generation". Be sure to feed in the names of your tables to that function. Then load the module in your browser: that will output the content for your own custom database_integrity.php file (to be placed in your module root folder).