Can the Tamino Database server be locked so that if one user is editing a XML Document another user can not do so until it is checked back in?
the Tamino kernel does provide transactional operations, but your question seems more like a “Content Management” question.
A certain amount of “check-in/check-out” functionality is provided by the Tamino WebDAV Server.
There are also some partner solutions available, in which Tamino is integrated into the partner’s Content Management system. You can find more specific information by contacting your local Software AG office.
I hope that helps,