I recently updated my Redshift ODBC driver and encountered a "Primary Key required for Update option" from the Output Data tool. This is a workflow that had been running fine prior to the driver update. Further testing confirmed that driver version up to and including 1.4.4.1001 worked fine, but later versions including the current version 1.4.8.1000 all had the same issue.
I opened Case #00311304, and was informed that the latest validated version is 1.3.7.1000, which is quite old and no longer available for download.
I am creating this idea to request that it is now necessary to make sure Alteryx is 100% compatible with the latest Redshift ODBC drivers.