They can and do use different replication models because their data model is explicitly wildly different from Postgres. For example, Postgres couldn't support e

They can and do use different replication models because their data model is explicitly wildly different from Postgres. For example, Postgres couldn't support eventual consistency even if it wanted to. You're barking up the wrong tree. As for Redis, sure, it has a simple master/slave system and Postgres could offer a similarly simple command UI that would let you issue a command instead of doing the current, trivial amount of setup. I don't disagree, but I think it's an inconsequential problem that affects a sysadmin/devops person about five minutes each year, and an issue that ultimately only deters dilettantes. The real problem to solve is dynamic promotion/demotion of masters and slave. It's not entirely trivial [1]. [1] http://redis.io/topics/sentinel http://redis.io/topics/sentinel