When applying a Cumulative Update to your SharePoint 2016 Farm, you might run into troubles when executing PSConfig/PSConfigUI after installing the Binaries. The error that is logged in the Windows Event Log looks as follows:
The Execute method of job definition Microsoft.SharePoint.Administration.SPUpgradeJobDefinition (ID ..) threw an exception. More information is included below.
The upgraded database schema doesn't match the TargetSchema. (Correlation=..)
You can avoid this issue if you either
With detached or already upgraded Content Databases PSConfig/PSConfigUI should run successfully.
My thoughts and findings about SharePoint 2016/2013/2010 and SQL Server