It would be helpful for Tableau Prep to include a stop button to terminate a database query, build such functionality into the Refresh Data button, or incorporate some sort of query timeout.
For example, if you lose your connection to an Oracle database while a query is being run, Tableau Prep waits indefinitely for the query to complete.
I likely initially experienced this because of an ongoing issue with my employer's VPN software dropping database connections, but I was able to reproduce it by manually disconnecting from my VPN and clicking the Refresh Data button. I was unsure if I should add this as a support case.
The user is ultimately forced to close the application. It is unclear if you can always save your work, but I found the following behavior using the following steps:
1. Open Tableau Prep and connect to an Oracle table
2. Make a change to the flow
3. Manually disconnect from VPN
4. Click the Refresh Data button
5. Close the application and choose to save
6. After a period of time the application will close and save. In the meantime, the user can still use the application, and it indicates that the flow has not been saved.
Nevertheless, the user experience of navigating query disconnects is confusing and likely to lead to lost work.