pattern or model, an examplar: how to let the end-user customize your app to fit his needs?

I'm trying to figure out from some time now how to devel开发者_运维问答op a functionality to let the end user create some additional fields in the system without affecting the db schema? I tried searching on google but i don't even know how ask the right question:) is it even possible? any hints will be appreciated.

regards, Rafal

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Why don’t you serialize the data into XML and store that? This way you don’t need to change the database at all. You could store the extra fields as a XML or VARCHAR(MAX) in the database.