Google Refine is a tool previously known as Freebase Gridworks that can be used to debug all kinds of tables, in order to avoid errors that as time has gone by can work out to be a great problem for any database.
How the program works
The program installs a simple server on your computer, to which you'll have access by means of the browser, from which you will be able to select the files that you want to normalize (already stored on your hard drive or embedded on a website). Once you have chosen the file, it will appear as if it were any old table, offering you the possibility to edit it (making use of the keys for repeated values, applying filters, eliminating fields,...), with the objective of making your database lighter.
An optimization tool for databases.
The application shares its aspect with the vast majority of web applications by Google, such as Google Calendar or Gmail, so that adapting to the interface will be much quicker if you've used this kind of tool previously.
If you're searching for a utility with which you'll be able to lighten the weight of your databases, download Google Refine as soon as possible.