DISCO validates overlay files before initiating the overlay process. If the overlay file fails validation, then the overlay card displays a downloadable validation report containing details of the failed validations.
To download an overlay validation report, on the overlay details card, click the more options button and then click Download validation report.
The validation report contains a Summary tab and a Data Load File tab. The Summary tab contains a description and counts for each validation check that failed or triggered warnings during overlay file validation. For each failed validation, the Data Load File tab contains samples of the rows in the overlay file that failed the validation.
Validations help decrease the probability that an overlay will have exceptions, but they do not eliminate the possibility altogether.
DISCO will also add a note to overlay cards that pass validation and complete but have warnings or exceptions. A warning on the card does not mean the overlay will not complete. It merely identifies overlays with warnings or exceptions that might warrant further investigation.