This looks like an issue on Vertica's end, not Tableau. If you click on "Show Details" does it show any further information? My guess is that Vertica has some sort of query timeout that is being reached and causing it to basically cancel the query (I believe Vertica has something called a Runtime Cap, which you should probably check). You can also take a look at the following discussion of that error on the Vertica Forum: https://forum.vertica.com/discussion/233258/vertica-v6-1-0-0-server-closed-the-connection-unexpectedly
Following up on this one. Let us know how we can help further.
Thank you for the help!
We have a time out option in vertica server. We rectified that.
Great. Would you please mark one of the responses as the "correct answer" so that we can close this thread and others can quickly find the answer if they have similar questions in the future?