AWS RDS 跨区域只读副本是否也复制用户和角色？

Question

I have a Postgres DB set up on AWS in region X and a read replica of that DB in region Y.

I'm about to perform 2 action in my source DB in region X:

1. Change the password of one of the users (ALTER USER my_user WITH PASSWORD 'password').
2. Revoke a role from one of the users (REVOKE my_role FROM my_user).

Will that change also replicate to the replica in region Y?

I couldn't really understand whether the replication only replicates data (table contents) or also user / role definitions.

Thanks! :)

Answer 1

Will that change also replicate to the replica in region Y?

Yes, Amazon RDS read replicas are meant to be a full clone of the primary database for various reasons such as implementing failure recovery .

Read replicas may need to be promoted to a stand-alone writeable DB instance in the case of the primary DB failing & this requires an exact copy.

Each PostgreSQL database contains a pg_catalog schema (in addition to public & user-created schemas) which contains the system tables and all the built-in data types, functions, and operators. This includes the pg_authid system catalog (table) which contains all the roles & 'users' ('users' since they are ultimately a role with login access).

Since Amazon RDS replicates all databases in the source DB instance (and thus schemas), any user or role changes to the source DB instance will be replicated on all read replicas .