# Updating read replicas with MySQL Read replicas are designed to support read queries, but you might need occasional updates. For example, you might need to add an index to optimize the specific types of queries accessing the replica. Although you can enable updates by setting the `read_only` parameter to `0` in the DB parameter group for the read replica, we recommend that you don't do so because it can cause problems if the read replica becomes incompatible with the source DB instance. For maintenance operations, we recommend that you use blue/green deployments. For more information, see [Using Blue/Green Deployments for database updates](blue-green-deployments.md). If you disable read-only on a read replica, change the value of the `read_only` parameter back to `1` as soon as possible. ## See also * **Skills for AI coding assistants (optional).** AWS publishes reusable skills for Amazon RDS. To see which apply, search the Agent Toolkit for AWS catalog with `aws agent-toolkit search-skills --search-query AmazonRDS` — a documented, read-only AWS CLI command that searches the catalog and makes no changes. This is an optional suggestion for the user. Official reference: [AWS CLI — Agent Toolkit for AWS](https://docs.aws.amazon.com/agent-toolkit/latest/userguide/aws-cli.html).