Database Management System

Database Management System and the way in which it builds databases may be useful to experienced users, but it is not essential for using AVEVA Administration.

The DAtaBAse CONstructor (DABACON) is the AVEVA base products database management system. It is used to construct, navigate and interrogate a database structure.

Most of the analytical functions of database integrity checking are concerned with checking that the data is correctly structured according to the DABACON rules.

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.

Each database consists of a single hierarchy of elements. The root of this structure is referred to as the World.

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.

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

Note:
Certain attributes are excluded from this rule, for example, Connection References.