A change is defined by two events:
# When the object changes the UpdateTimeStamp is set. An object is meant to be changed when at least one of its properties has been changed. To know this every property will be asked if it has been changed or not (properties hold this information by themselves). A change of a property means either:
*#* it’s value has been changed (the property knows its new and old value),*#* it’s ValidationTimeStamp has be set
# When a new primary child is added to a relation. Primary in this context means the first level of object relation, the directly connected object so to say. That means adding such a child counts as a change for the owner object and the UpdateTimeStamp will be set. A child can be anything (Attributes, Relationdata, etc).