Visitor Data Mart (VDM) data extractions can contain duplicate visitor entries


Webtrends Visitor Data Mart


Visitor Data Mart (VDM) data extractions that are created during a data load cycle have a small chance of displaying duplicate entries for a visitor if a visit session for that visitor is currently being loaded by the VDM data loader process.

In essence, the extraction reads and extracts a row for a visitorID, which is subsequently changed by the loader process. This results in updated entries for that visitorID, which are then picked up again by the extraction process. This stems from the fact that loading new data and extracting data are not mutually exclusive operations.

This functionality is being reviewed for possible future changes.Webtrends recommends post-processing to remove the duplicate entry but no general solution fits all cases.