Can we identify which users accessed which on-premise data sources?
Both PBI Service and Report Server are being used for reports.
1. Seems like the audit logs for PBI Service can return "ExploreDataset" events with a "User" attribute. Does this also apply to on-premise data sources? It shouldn't matter whether the dataset is on-premise or on-cloud, right?
2. For on-prem scenarios, does either Report Server or the On-premise Gateway have logs identifying which users accessed which databases?
3. For Desktop connections, users connect directly to the databases, so access audit should be taken directly from the databases. Is that right?
For PBI report sever, look at the report server catalog database. It has a SQL view ExecutionLog3 that should include information about what has been accessed.