How to manage the versions of databases ?

Hello,

[Quoted] [Quoted] In my company, we sell a huge software that uses huges databases, and we [Quoted] [Quoted] modify the scheme of the databases almost every 3 months. [Quoted] This is very complex to manage for our customers, and we have to manually make big changes in their databases.

[Quoted] [Quoted] We are looking for a way to manage rightly these updates, and we already [Quoted] have some ideas, but we can't imagine being the first company to deal with that hard problem.

[Quoted] [Quoted] So may you give us some URL pointers to web pages explaining how it's [Quoted] [Quoted] usually done, or explain us the theory of updating a database model. I suppose that some tools exists, so perhaps you know one of these tools.

Thank you in advance.

-- 
Nicolas Ecarnot | E-mail: nicolas.ecarnot_at_bigfoot.com