We have multiple users assigned as Owners for most of our Quicksight content which means they can edit the same dataset based on a custom SQL query off a database. If 2 users were to edit this dataset simultaneously and then try to Publish, would there be a prompt to either? If so, what is the prompt and when does it appear? When the first user to click Publish does so, informing them there were other changes while they were working or the other user, telling them that another version has been published in the meanwhile? Or is there no prompt and whoever Publishes last, their changes stay? Or is there a lock system in place that does not even allow editing the same dataset by 2 users at the same time?
There is no lock to disable editing datasets at the same time.
In regards to a prompt there is none as well and it works like most other databases. Whoever made the last publish would overwrite the other publishes.
One thing to note, is that there are versions of your published datasets available to you.
Hope that helps