OPTIMISTIC VERSIONING CONCURRENCY SCHEME FOR DATABASE STREAMS

Aspects of the subject matter described herein relate to versioning for databases. In aspects, two or more users may share the same version of data, such as a report, in a database. One of the users may seek to update the data. In response to a request from the user, a new version of the data is created. For data that is not updated via the request, the new version shares data with the previous version, thus saving space. For data this is updated, new segments within the database are created to store the updated data. Each user is allowed to access the data without blocking other users accessing the data.