When the Content Acquisition System creates a new Record Store instance for a data source, CAS uses all record properties as change properties. In other words, CAS evaluates all properties on a record to determine if the record is different from the previous generation's record in the Record Store instance.

If desired, you can restrict the number of properties that CAS evaluates by configuring the changePropertyNames property. This improves performance by allowing CAS to check a sub-set of record properties when determining if a record has changed. In addition, CAS can check only properties that are meaningful to the data. For example, you can set a change property to check a file version number rather than a property for fetch time or trivial information.