The consistent view (Is data or OMS version) which is used at the moment was canceled. This is due to the fact that either the maximum time limit for a consistent view was exceeded (database parameter: MaxRetentionTime) or that a memory bottleneck occurred and the specified time limit in the database parameter MinRetentionTime was exceeded.
Make sure that consistent views do not exists for too long (e.g. with suitable commits) or increase the parameter accordingly. A parameter increase however will make data volume grow since old object versions have to be stored longer.