Now you can configure your app to add only the data that’s new since the last dataset update. This change reduces network loads, can speed up dataflow jobs for large datasets, and helps you stay within your limits. No more worrying about updates leading to duplicated data across multiple datasets and counting against your row count limits.
Where: This change applies to Enterprise, Performance, Unlimited, and Developer editions.
Who: This change is available to customers who purchased Salesforce Shield or Salesforce Event Monitoring add-on subscriptions.
How: To enable this beta feature, contact Salesforce. Then, in the configuration wizard, select Add only new event log file data to existing datasets?. The app then adds only the new data and deletes all data that’s dated outside of your specified retention period.
This configuration is available only in new apps. To add it to an existing app, delete the app, and then recreate it. Enable the Add only new event log file data to existing datasets? setting in the configuration wizard.
Append New Data to Event Monitoring Analytics App Datasets (Beta) (salesforce.com)