Amazon web service provides both relational database services and non-relational database services. AWS customers now have three cloud based database solutions available:
Amazon SimpleDB service – Amazon SimpleDB can be useful for those who need a non-relational database for storage of smaller, non-structural data. Amazon SimpleDB has restricted storage size to 10GB per domain and it can achieve up to 25 writes/second. Amazon SimpleDB offers simplicity and flexibility. SimpleDB automatically indexes all data. Amazon SimpleDB pricing is based on your actual box usage. You can store any UTF-8 string data in Amazon SimpleDB.
Amazon DynamoDB service – Amazon DynamoDB can be useful for those who need a fast, highly scalable non-relational database. There is no limit on the storage size per table and you can specify how much request capability you require. Amazon DynamoDB offers good performance and incremental scalability. DynamoDB indexes only the primary key, which can be a composite primary key. DynamoDB is priced according to how much request capacity you have requested. You can store Strings and Numbers.
Amazon Relational Database Service (Amazon RDS) – Amazon RDS can be useful for those who need relational database service that offloads database administration. Amazon RDS provides the full capabilities of MySQL or Oracle database. Amazon RDS Database instances are instances of familiar MySQL or Oracle databases, running on an EC2. RDS offers backup/restore of databases scalability, and allows you to have up to 1TB database size.
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