Versioning

Different versioning strategies allow freezing the state of single object instances or a complete database. Several versioning strategies may be combined:

• version scope - defines the scope for consistent version numbers (database, object space, owner or instance)
• managed - provides a hierarchy of major and minor versions, where major versions define consistent version states and may be assigned to timestamps.
• synchronized - version numbers are synchronized representing a temporal order of changes

Moreover, online schema evolution allows extending a database schema without reorganizing running databases. Schema version uses managed versioning for the resource database, i.e. creating new schema versions will freeze the current schema version, which allows upgrading object instances later at run-time.