As of TDV 8.2, gathering statistics on a data source which uses passthru authentication is not supported. In order to gather statistics without using the process owner id of the TDV instance, one must provide explicit credentials in the data source.
Combined with the MPP dependency on accurate statistics, this creates a workflow wherein TDV users will need to regularly provide credentials, refresh statistics, and remove the credentials again.
Please add support for using kerberos passthru credentials to gather statistics.