US Patent 9037825 Write horizon data management

Conditions are enforced to prevent unintended deletion of data stored by a data storage system. For example, to delete a collection of data, a condition on the collection of data's size may be enforced. The collection may be required to be empty, for example. In addition, a condition that there not exist a pending data processing operation that can affect fulfillment of the condition on the collection of data's size is also enforced.