File import process

After a file transfer service is assigned to a file import data source, you upload files to the service. The system then uses the following order of operations:

1. Check for New Files
   The system checks the file transfer service for new files every 10 minutes.
2. Copy New Files
   When a new file is detected, it is copied from the file transfer location and processed in the Customer Data Hub.
3. Match Filename Prefix to File Import Data Source
   The prefix of the filename is used to identify which file import data source to use when importing the data in the file.
4. Process Files
   The header line is read to identify the attributes being ingested. From there, the following processing is performed:

• Visitor Lookup
  The visitor ID is used for a lookup of the visitor record in AudienceStream. If an existing visitor record is not found, a new one is created.

Grouping rows with the same visitor ID increases the speed of the import.

• Attribute Enrichment
  The visitor record is enriched according to the attributes imported and the existing enrichments in your account.