Amazon Aurora

It means that SQL code, drivers and other tools that you are using in an existing PostgreSQL environment should work just the same for Aurora for PostgreSQL. In terms of how the components fit together, Aurora uses a custom architecture that includes its own storage/replication/redundancy, transaction management, query optimization and caching/buffer mechanisms. I'm sure my description barely scratches the surface and web searches will provide a wide-array of "high-level" architectural designs. I guess my point is what's under Aurora's hood is fairly proprietary and you can't really compare it to conventional RDBMS.

Thanks for contacting AWS. I understand that you would like to know if there is any Hard limit on the number of schemas that can be created in Aurora Postgres instance. I have researched on the query and could confirm that there is no hard limit set for the number of schemas that can be created in Aurora Postgres . Your understanding is correct in terms of Postgres limits as no such hard limit is imposed. Only hard/Soft limits for Aurora are these : [+] https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/CHAP_Limits.html : Quotas and constraints for Amazon Aurora However, The higher the number of schemas you create , Higher the resources consumed. As long as you have sufficient storage ( In case of Aurora, storage is auto scaled so this not an issue ) and Right instance class there should not be any issues with 'n' Schema creations. I Hope this helps !

No RDS product supports "real-time" replication across regions. Cross-region replication is always asynchronous.

You can expect to see a higher level of lag time for any Read Replica that is in a different AWS Region than the source instance, due to the longer network channels between regional data centers.

https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html#USER_ReadRepl.XRgn

Additionally, cross-region replicas for Aurora/Postgres are not yet available.

Cross-region replicas are only available for Aurora/MySQL... but a cross-region replica is not for zero downtime or failover, anyway -- it's only for geo/latency-based read scale-out or disaster recovery, because once you promote the replica, the original master has to be abandoned, because replication is one-way.

If, when you said "region," you were actually referring to availability zones, then that is much more straightforward, since the backing store of Aurora instances is replicated across 3 availability zones within the region, and replication is synchronous. All replicas in a single region can be synchronous, even in different AZs, since they all share the same replicated storage.