Rational Software's ClearCase version control system stores almost all of its information in databases. These aren't proper databases, like Oracle or Informix, but instead are home-grown databases, which Rational refer to as Versioned Object Bases, or VOBs for short.

As well as storing the text of all the elements (files and directories), ClearCase VOBs also store 6 different types of metadata (attributes, branches, element types, hyperlinks, labels and triggers).

About the only kind of data which isn't stored in a VOB are:

• the text of checked out files, derived objects and other view private files, which are stored in the users' individual views and

• the record of which VOBs and views exist and where they are physically located, which is stored in the registry.