hi ,
In order to check databases for changes .you can use the tools like Toad or DB visulaiser . the first thing you need to do is establish a connection between the tool and your database.for that you need to find out from your DBA to which server database it is connected and what schema is it in and login details like user -id and password. If you are using toad or DBvisualizer .you can see all the columns in the tables, indexes, rowcount,primary keys , references of that table. and by writing simply queries u can check the functionality of the feilds.