The Ozone Backend uses the Ozone object-oriented database to persist topic map information. The Ozone database manages large collections of Java objects through the use of Java object serialization with paging and caching as well as other advanced database management techniques. The database is simple to install and to maintain and is written entirely in Java. The database can be run in either a client-server mode enabling multiple applications to connect to and manipulate the data simultaneously, or as an embedded server which runs in the same JVM as the application which accesses and manipulates the data.
Currently this backend implementation does not support transactional updates to topic maps, although this is a planned feature for a future release. This means that currently the Ozone backend is best suited to applications restricted to a single user, where the size of the topic map exceeds that which can be comfortably managed by the in-memory backend, or where the persistence of every change made without the need to explicitly export the topic map is important.