I have a Journey where it does a decision split based on a Data Extension Status field = Planned. I am using the "contact data" evaluation option as the status can change from the time the person is initially injected into the journey.
Eg: Person enters the journey as status = planned however along the way have their status changed to cancelled or rescheduled.
Based on these changes the person will take a different route.
When using contact data i get this message "At least one attribute in this filter criteria could produce multiple matching values. By default, Journey Builder uses the first matching value. You can use attribute-to-attribute comparison to determine the right match"
I have a primary key based on the event ID so this is unique and will only be in the data once, however a person could be in the Data Extension multiple times over the period of a year with different Event ID's.
My Question is when the Journey does a match to check the record is it based on the Data Extension primary key or Subscriber key?