Amazon Relational Database Service (Amazon RDS) is a managed relational database service with a choice of six popular database engines, namely, Amazon Aurora, PostgreSQL, MySQL, MariaDB, Oracle, and Microsoft SQL Server. Amazon RDS is available on several database instance types - optimized for memory, performance or I/O.
RDS provides cost-efficient and resizable capacity while automating time-consuming administration tasks such as hardware provisioning, database setup, patching and backups. It frees you to focus on your applications. You can also use the AWS Database Migration Service to easily migrate or replicate your existing databases to RDS.
RDS thus makes it easy to set up, operate, and scale a relational database in the cloud. RDS benefits include: Easy to Administer, Highly scalable, Available and Durable, Fast, Secure and Inexpensive. RDS use cases include: Web and Mobile Applications, Ecommerce Applications, Mobile and Online Games.
DB Instance Classes
Amazon RDS currently supports the following DB Instance Classes with varying configurations ranging from small to large to 10x large.
M4 (Standard - Latest Generation)
M3 (Standard - Previous Generation)
R3 (Memory Optimized - Current Generation)
T2 (Micro Instances)
Configuration sizes include micro, small, medium, large, 10xlarge etc. Not all configuration sizes will be available for all instance types. For example, T2 (Micro Instances) has only micro, small, medium and large.
Amazon RDS Pricing
Prices varies between instance types (e.g. M4, M3, R3, T2) and their configuration sizes (e.g. micro, small, medium, large, 10xlarge etc.)
The AWS Free Tier for Amazon RDS includes 750hrs of Micro DB Instance each month for one year, 20GB of Storage, and 20GB for Backups.
Reserved Instance Pricing
Reserved Instances are appropriate for steady-state database workloads and offer significant savings over On-Demand. You commit to the entire duration of the Reserved Instance term and pay an upfront charge and a discounted hourly rate. You will be billed for each hour of the term regardless of usage.
One Year Reserved Instances provide discounts up to 44% and Three Year Reserved Instances provide discounts of up to 63% over On-Demand.
RDS is mostly suitable for OLTP while Redshift is for OLAP.