Performance Improvement with Caching and Delta Tracking

OData delta change tracking is a method by which a client obtains changes from a data store without downloading the entire data store. Set up your application to track deltas in your application configuration file when you configure your defining requests. If your OData Producer supports delta query protocol to track changes, the provided delta links are automatically used to track changes and you need not configure delta tracking. When possible, use an OData Producer that supports delta query protocol.

• When to use delta tracking

  Delta tracking sends only changed data to the client, rather than the entire data set. This significantly decreases the load on the back end and is especially useful when performance is critical.

  • If your OData Producer does not support delta change tracking, the default delta tracking setting in the application configuration file tracks deltas using SAP Mobile Platform Server. This improves performance on the client, while tracking deltas using the OData Producer improves performance over the entire network.

  • If your OData Producer has limited support for delta change tracking, for example, deltas are configured to expire after a set period of time, using the always setting for delta tracking in the application configuration file helps replace missing delta tracking functionality.

• When not to use delta tracking

  If all or most of your data is continuously changing so that you expect to be downloading the full payload during every refresh, enabling delta tracking does not improve performance. For example, if you download the temperature value for sensors in 1000 offices, using delta tracking does not decrease the amount of data downloaded during a refresh and turning off delta tracking may increase performance.

To minimize the load on the OData Producer and possibly improve performance, cache data that is shared by numerous users on SAP Platform Mobile Server. For example, cache data from a query that returns the same results to multiple users. Do not cache user-specific data. For example, do not cache data from a query that returns different results to each user. Set up your application to cache data when you configure your defining requests in your application configuration file.