The principal data objects in DABACON are element instances. In general, these elements represent physical entities such as pipes or valves. These elements are associated with one another in a hierarchy: for example, a Pipe will own Branches which own Valves. Each element has attributes to describe the properties of the item it represents: for example, Temperature, Pressure, Length.

The valid element types, and their attributes, are defined in the database schemas. There are different database schema files for each databases type, for example, Catalogue and MODEL databases.

Database changes are made during a database session. On SAVEWORK, FINISH or module switch, the changes are appended to the database. If the user QUITs rather than saving a session, the changes will be lost.

Multiwrite databases allow two or more users to write to the same database at the same time. The system checks that no two users write to the same element. The changes are then written back to the database as new sessions in the normal way.