It is true that something like pg_logical doesn't suffer from those three things but it does suffer from others:
* No DDL - Agreed, not "required" but certainly a very nice feature.
* Lack of simplicity
Users, like simple. It is one of the key reasons there is a migration to the cloud, simplicity. Everything from scaling, to pricing, to provisioning etc...
Well, you can't run DDL during pg_upgrade either. I've never seen a solution that supported that, and if it did, it would certainly violate the "simple" rule you advocate.
Simplicity is key, I agree. But that's just a user interface feature, not a comment on what's underneath the covers. pg_upgrade is not simple and is never likely to be so, under the covers.
Anyway, I'm cool if you don't want to use it, for while or never. Options are good.
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Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services