Our company is progressively superseding the deployment of hosts with SQL Server installed, while moving towards the usage of SQL Server instances provided by AWS' Relational Database Service as the DB backend. Although currently OSISoft does not officially support the usage of RDS instances as backends for AF and PI Vision, we performed some internal tests with both AF and Vision and they seem to be promising. We would like OSISoft to study this kind of solution and, if there are no major obstructions, provide official support for such scenarios.
Can you define the items required for troubleshooting, that you can't obtain from a managed database?
You can obtain a lot of data from the managed servers (including message logs and metrics). Most companies lean toward managed databases to streamline teams.