This functionality is useful when your data record model is a combination of various properties that come from multiple sources (for example, interaction history, social media platforms, purchase history, location information, subscriptions, and so on) and the update frequency for these properties differs.

1. Access the Data Flow rule that you want to edit:
   1. In Dev Studio, click RecordsData ModelData Flow.
   2. Select a data flow that you want to edit. This data flow must have a Decision Data Store data set configured as its destination.
2. On the Data Flow tab of the selected Data Flow rule, locate the Destination shape that outputs data to a Decision Data Store data set.
3. Double-click on the Destination shape to open its configuration window.
4. In the Save options section, select the Save a field within the record check box.
5. Place the cursor in the empty field, press the Down Arrow key, and select the property that you want to update as a result of running this data flow.
6. Optional: Only for page list properties that are exposed and optimized for appending, select the Append check box. If you select the Append option, instead of overwriting the existing property value with the new one, Cassandra creates a list of property values. This option is useful, for example, if you want to track all the clicks that the customer makes on your website, instead of only the most recent one.
7. Click Submit.