I recently experienced the same problem with Tableau 8.0.5 Desktop when setting this up on a colleagues new machine. I haven't found a solution to the problem at the moment. On my own machine this worked worked an earlier version of Tableau Desktop when I was using a trail version I downloaded a few months earlier. So my guess is this was recently introduced with 8.0.5.
Any suggestions on workarounds would be greatly appreciated.
I did use the ODBC connection to Redshift which does not get exactly where you need to be, but it's a start. I'll post if I find any magic answers, but good to hear that its not just me!
This is what I heard from Tableau Beta support:
"The core issue is that cursors are not currently supported on single-node Redshift instances (only multi-node instances). Tableau 8.1 and 8.0.5 uses cursors by default to enumerate schemas, which is why single node instances are missing them.
Amazon is adding support of cursors on single-node Redshift instances but we do not have an ETA yet."
Cursor support has been added for single-node Redshift instances. Please upgrade to the latest Tableau maintenance release 8.1.3 (or 8.0.7) and any single-node cursor issues should be resolved.
Product Manager, Tableau Software