Coalesce is set in the Transform Map. It is a property of a field used in transform map field mapping. It is just a true or false value between a source Import Set field and a target table field. Coalescing on a field or set of fields facilitates us to use the field as a unique key. If it finds a match using the coalesce field, ServiceNow will update the existing record with imported information. If a match is not found, then it inserts a new record into the database.
