Amazon Relational Database Service (RDS) is a cloud-based managed relational database.  AWS handles routine tasks like provisioning, patching, backup, recovery, failure detection, and repair of your databases.

Amazon RDS utilizes Read Replicas to enhance performance.  It can also replicate the database across multiple Availability Zones for durability.  Automated backups are stored in Amazon S3.

You can pay On-Demand or purchase Reserved Instances, and you can pick from a variety of Instance Types to fit your needs and budget.

AWS Database Migration Service allows you to easily migrate or replicate existing databases to AWS.

If you wanted to have a database that is unmanaged (you manage everything about the database including updates and maintenance), you should host it on an Amazon EC2. You can also deploy Amazon RDS on-premises using Amazon RDS on AWS Outposts.

6 Database Engines Available in Amazon RDS

• Microsoft SQL Server
• Oracle
• MySQL Server
• PostgreSQL
• Amazon Aurora (with MySQL compatibility and PostSQL compatibility)
• MariaDB

There are 7 database engines available now, if you count the 2 engines available with Amazon Aurora separately.

Amazon Aurora

Amazon Aurora is a cloud-based, fully-managed, MySQL and PostgreSQL compatible relational database.  It is cheap, fast, fault-tolerant, and scalable. It provides commercial-grade database performance and availability at 1/10th of the cost.

It’s up to 5 times faster than MySQL, and 3 times faster than PostgreSQL while providing the same security, availability, and reliability.

Amazon Aurora is fully managed by Amazon Relational Database Service, which automates administration tasks like provisioning, patching, backups, and database set up.

It features an auto-scaling, distributed, fault-tolerant, self-healing storage system with up to 15 low-latency Read Replicas.  It can also replicate data across 3 Availability Zones.

Resources

• Amazon RDS (AWS)
• Amazon Aurora (AWS)
• Read Replicas (AWS KB)