RDS is AWS managed relational database service.

What RDS manages

With RDS, AWS handles much of the database infrastructure work.

RDS can help with:

• Provisioning database instances.
• Backups.
• Patching.
• Monitoring.
• Replication options.
• Failover options.

You still design schemas, indexes, queries, permissions, and application behavior.

Supported engines

RDS supports engines such as:

• PostgreSQL.
• MySQL.
• MariaDB.
• Oracle.
• SQL Server.

Amazon Aurora is a cloud-optimized relational database compatible with PostgreSQL or MySQL.

Backups

Automated backups allow point-in-time recovery within a retention period.

Manual snapshots can be kept longer and copied across Regions when needed.

Backups are not useful unless restore is tested.

Multi-AZ

Multi-AZ deployment keeps a standby database in another Availability Zone.

If the primary fails, RDS can fail over to the standby.

Multi-AZ improves availability. It is not primarily for read scaling.

Read replicas

Read replicas copy data from the primary and can serve read traffic.

Use them for:

• Read-heavy workloads.
• Reporting queries.
• Reducing primary database load.

Replication lag must be considered.

Connection safety

Databases can fail under too many open connections.

Backend systems should use:

• Connection pooling.
• Reasonable timeouts.
• Private subnet placement.
• Security groups allowing only app access.

Quick revision

• RDS is managed relational database hosting.
• AWS handles infrastructure tasks, not schema quality.
• Automated backups support recovery.
• Multi-AZ improves availability.
• Read replicas help scale reads.