Exam AWS Certified Database - Specialty topic 1 question 25 discussion

Correct

Developers would still need to wait hours for the restore to complete, in case of mistakes in their schema updates. But if we try to avoid this, the other option C requires migration to Aurora! and even then "Multiple team members are working on the project, making it difficult to find the correct restore point for each mistake." It is a tough call. https://serverfault.com/questions/791359/how-do-i-make-an-aws-rds-mysql-read-replica-have-a-different-schema this shows how read replica can be used for writes.. with some limitations..

That's why C is correct: Migrate to Aurora MySQL, there you can use the BackTrack functionality which is not available in RDS MySQL.

yes C is the answer.

Yes you can write to MYSQL readable replicas as mentioned here https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html

if using clone then will be OK but not Replicas - Read only

Mmmhh now I saw the exact same question in an Udemy Exam Course and the authors are saying it is indeed Answer A with the following explaination: "For the given use-case, each developer can perform DDL operations for the schema changes on the MySQL read replica once the read replica is in sync with its primary DB instance. Then the developer can promote the read replica and direct the application to use the promoted instance during the development phase. This solution isolates the schema changes done by each developer to their own promoted instance. This also avoids the problem of keeping track of the "correct restore point" that the team faced while using the same DB instance. If you need to make changes to the MySQL or MariaDB read replica, you must set the read_only parameter to 0 in the DB parameter group for the read replica. You can then perform all needed DDL operations, such as creating indexes, on the read replica. Actions taken on the read replica don't affect the performance of the primary DB instance."