Delta Propagation describes how deltas (updates to data) are propagated and how to implement delta propagation. It also analyzes performance limitations.
In most distributed data management systems, stored data is created once and updated frequently. Updates are sent to other members for event propagation, redundancy management, and cache consistency in general. Tracking only the changes in an updated object and sending only the updates, or deltas, mean lower network transmission costs and lower object serialization/deserialization costs. Generally, the larger your objects and the smaller the deltas, the greater the performance benefits of delta propagation. Partitioned regions generally benefit more with higher redundancy levels.