Warning: If the upgrade encounters non-compliant projections, it regards them as unsafe and the upgrade will fail. You must then revert to the previous installation.
Solution: Download and run the pre-upgrade script.
The pre-upgrade script analyzes your current database and identifies unsafe projections. It then generates a DDL script that you can use before the upgrade to remedy these projections and ensure compliance with system K-safety.
For more information, go to the download page: https://my.vertica.com/9-1-pre-upgrade-script/
The blog link is here: https://my.vertica.com/blog/upgrade-fix-unsafe-buddy-projections/