VOB schema versions
Each VOB has a database schema version that defines the format of the VOB database and therefore determines the types of data and metadata that the VOB can store.
New schema versions are introduced very rarely, and schema version numbers are not necessarily sequential. DevOps Code ClearCase® supports schemas 54, 55, 80, and 81. All schemas provide support for VOB database files larger than 2 GB. Schemas 80 and 81 provide support for element access control lists. Schemas 55 and 81 provide support for semi-live reformatVOB. In some releases, a particular schema version is necessary for supporting functionality in the release. It might also be necessary to raise the VOB feature level to enable that functionality (see VOB feature levels).