The database system uses consistent views to guarantee read access to an object, independently of any changes being made to the data by other transactions. A consistent view can extend across one or more transactions (OMS version).

When a user opens a transaction, the user retains his or her view of the data until the transaction ends. Any changes made to the data in the meantime by other transactions do not affect the first user’s data view.

When an object within a consistent view is accessed for the first time, the database system copies this object data to the OMS heap. If multiple consistent views access the same data, the database system copies the data for each consistent view to its own separate area of the OMS heap. When a consistent view is closed, the database system deletes the corresponding data in the OMS heap.