There is also the philosophical question of why you would choose an open source database server product to build a closed source database. Many people have contributed to the project in the firm belief that open source is the best way to provide software.

But, more particularly, when it comes to the storage of users' data I am a firm believer that the users should insist on the ability to access their own data – which will often include the need to understand the structures and the processes you have built (the metadata). If you go out of business or become otherwise unavailable it may be of critical importance that the users can at least extract their own data (in appropriate formats) in order to be able to move to alternative systems.

Can you trust the users to respect your intellectual property while you are still in business and available? Provide the necessary services and facilities and hopefully they will. If not, there is a good chance that there is little you can do to stop them.