Query Activity appends Data Extension instead of overwriting information
|Knowledge Article Number||000220946|
A Query Activity that's set to overwrite the Data Extension doesn't overwrite as expected. Instead, information is appended in the Data Extension. This is because the external key for the Data Extension has been modified since the creation of the Query Activity. If the name of the Data Extension doesn't change, but the customer key of the Data Extension does, then the erasure action of the Query Activity will silently fail. This will cause the previous data to be retained and the new data to append to the existing data.