It is a well known fact in the database community that the ACID properties of transactions are too restrictive for long lasting collaboration efforts. Anfindsen (1997) shows that the only ACID property we really want to compromise is that of isolation. He presents a solution to the problem of long lasting transactions, namely the Xymphonic transaction model.
It is argued in this thesis that there are many good reasons for beingable to create versions in general, and more specifically in connection with Xymphonic transactions. The main result of this thesis is a solution of how the Xymphonic model can be combined with features from the field of versioning. It is shown through a prototype implementation that the proposed solution is fully functional. The solution, however, does not claim to be either optimal nor complete, and a chapter is devoted to outlining some interesting areas of further work.