Hard: asking them to write migration code of any kind, much less understand tablespaces and replica placement.
By that standard, any kind of global consistency (or even weakened consistency of various kinds, but maintaining some desirable properties) will always be 'hard'.
It will always be hard. Consistency + latency is a huge problem.
We can give _most_ developers the benefit of globally distributed postgres without causing consistency issues, though. Read replicas are simple to think about and reasonably easy to write standard code for.
Comments
By that standard, any kind of global consistency (or even weakened consistency of various kinds, but maintaining some desirable properties) will always be 'hard'.
It will always be hard. Consistency + latency is a huge problem.
We can give _most_ developers the benefit of globally distributed postgres without causing consistency issues, though. Read replicas are simple to think about and reasonably easy to write standard code for.
Yes, this is a hard problem.