After records have been identified as duplicates, there needs to be some mechanism to decide, which of the attribute values are chosen for the deduplicated, merged record.
The following cases may occur:
- an attribute value is only specified in one of the records
- an attribute value is specified in both records
Options to proceed are:
- value update - replace the older value (only one value is allowed)
- value merging - add another value to the (until then incomplete or outdated) set of values
The complexity of this mechanism does not need to better than the legacy system for now. A more advanced version of this issue is described in DD-722.