Amazon is rolling out a limited beta of the latest scalable SaaS offering, a database called "SimpleDB." Together with the previously offered Elastic Computing Cloud (EC2) and Simple Storage Service (S3) components of their web services, this completes the troika that acts as a foundation for most modern websites: processing, file storage, and database.

It will be interesting to see how SimpleDB fares; the rates are, as with all Amazon Web Services, dirt cheap, but the service is every bit as simplistic as the name implies. At least so far as the exposed API is concerned, the database is basically an old-fashioned flat file, a sort of souped up spreadsheet of columns and rows (with a few distinctions which would not be unfamiliar to any pre-relational database developer). That's probably fine for a lot of applications, but most modern web developers rely on a deep and intricate control over the relations in their data, and any significantly complex website probably owes more to the design of its backend database than to any other single feature. Whether or not designers can adapt to Amazon's concept and simplify their data model (or rather, rely on Amazon's data model) may determine the success or failure of the offering.

Of course Amazon will be happy to provide EC2 services for anyone who feels the need to develop and run their own relational database and no doubt many will do so. But anyone who can take advantage of the SimpleDB offering instead will probably find it less expensive and easier to manage.