I am in a situation where I am having to choose whether I should Add/Update or Overwrite in a Daily Batch File Import into a Data Extension which I plan to use in Decision Paths in Journey through the contact data model (not journey data). Is it true that if my import type into this DE is Overwrite, it will cause issues as the _CustomObjectKey will change?
Also, can someone explain what _CustomObjectKey is? Does each DE record have a unique _CustomObjectKey or is it one per key per DE? How can we find the out _CustomObjectKey?