Which method retrieves only changed values within a given time?

The method that retrieves only changed values within a given time is Delta Retrieval. This approach is particularly efficient because it focuses on capturing only the data that has changed since the last retrieval, minimizing the amount of data transferred and processed. Delta Retrieval is essential for scenarios where real-time data monitoring and analysis are critical, as it allows for quick updates without overwhelming the system with unnecessary data.

Other methods mentioned serve different purposes. Full Retrieval collects all data points for a specified period, regardless of whether they have changed or not. This can lead to a significant amount of raw data being processed, which may not be efficient in real-time applications. Periodic Retrieval retrieves data at set intervals but does not specifically target changes, leading to potential redundancy in the data collected. Snapshot Retrieval captures the data at a specific moment in time, providing a complete picture but again, without differentiating between changed and unchanged values.

In contexts where performance and data management are crucial, Delta Retrieval stands out as a streamlined and effective choice.