Explain owner credentials versus viewer credentials.

With owner credentials, every query runs as the data source owner. Viewers need no access to the underlying data, which is how you share a BigQuery-backed report with people who have no BigQuery access.

With viewer credentials, each person queries as themselves and sees only what their own permissions allow — effectively delegating row-level security to the source system.

The risk with owner credentials is exposure: anyone who can open the report can see everything behind it. Choosing owner credentials on a sensitive source and then sharing the report broadly is the most common data-exposure mistake in the tool.