ODABA database

The ODABA data model consists of data stored on different data levels:

• Data - On data level, facts of the real world are reflected as states of an observed objects. The way data is structured is described on the schema level.
• Schema - On schema or metadata level at least the schemes for presenting object states (data types) are defined. In many cases, the schema level also provides methods (functions, forms, templates) and causality definitions (event-reaction).
• System schema - Since metadata is data, again, it requires a schema (or metametadata), which is defined in the system schema, which is also data. Because data on this level is self-describing, is does not require another upper schema.

Data on each level is stored in a specific ODABA database with a schema depending o the data level.