AWS RDS has an Automatic Minor Version Upgrades feature.
AWS says:
a minor version upgrade includes only changes that are backward-compatible with existing applications.
Is there any reason to think that Canton poses any unique issues related to minor version upgrades? Would you go ahead and enable Automatic Minor Version Upgrades?
Canton uses standard Postgres features. We have no reason to think that Canton would pose any unique issues related to minor version upgrades. The DA Release Notes list the Postgres versions we have run our tests against.
As with any application, your overall system would need to be robust to having the database down for as long as AWS requires. Unless the services are paused, there will be timeouts trying to connect to the database. If you have alerting configured around those logs, those will be triggered, etc. What will be the user experience during this time? But, those are not Canton-specific issues.