This information applies to version(s): 1, 2, 3, 4
As with all plugins of Photoshop or Lightroom, DxO ViewPoint makes corrections either on a TIFF copy of the original files (Lightroom) or on a buffer loaded in Photoshop after Camera RAW is closed.
When used as a plug-in for DxO PhotoLab, the non-destructive workflow is available. In this case, changes are saved in the sidecar files of DxO PhotoLab.
DxO ViewPoint standalone version does not work in a non-destructive workflow.