Each operation is implemented by a method, plus there may be additional methods defined. 2.6 state State is modeled by the properties of an object. A property can be an attribute or a relationship. The attributes and relationships of an object are defined as part of the type interface. Literals always exist implicitly.
Most queries return literals.
The query language contains expressions for constructing objects, but there is no mention of lifetime of these objects. See also 9.1 Relationships . The model assumes operations are executed sequentially, although it does not preclude concurrent or parallel operations. The model supports nested transactions, where the commit of a nested transaction is dependent on the containing parent transaction's commit. Type Transaction defines operations to begin, commit, abort and checkpoint a transaction.