There are press articles and some blog posts here and here that is comparing SQL Server Data Services to Amazon SimpleDB or S3.  If we look at the data model and query capabilities of SSDS as described by Nigel Ellis here, it is not hard to see why.  The data model is entities scoped to containers.  Containers can contain a heterogeneous collection of entities.  The key is that there is no requirement to define a schema.  Entities themselves are just simple property bag with a few fixed properties (ID, Kind, Version).  Properties are just name - value pairs where the value is a scalar.  A container is the unit of consistency and scope of all operations.  An entity is the smallest unit of storage.  We kept the service simple on purpose as we want to make sure that it is very approachable and the barrier to entry for a developer is not too high.  Our desire to keep it simple is what I think is creating some confusion and comparison to the other services out there.  If we think of SSDS in isolation, the comparison does hold some water.  So let me see if I can make another way of thinking about it stick.

The way we think about it is as an extension of the Microsoft Data Platform to the Cloud.  It is part of a comprehensive Data Platform that includes SQL Server, SQL Server Analysis Services/Reporting Services/Integration Services, SQL CE, SQL Express, ADO.Net , Microsoft Synch Framework etc.  It gives developers one more tool in their tool chest to build interesting scenarios in the new Software plus Services world.  Software plus Services is Microsoft's strategy and it is a mouthful.  So let me take a crack at explaining how Software plus Services can create more value than just Software or Services alone.

One of my favorite example of a compelling software plus services offering is Exchange, Outlook and Exchange Hosted Services.  We deliver Exchange as a server product, Outlook on the desktop, Pocket Outlook on my mobile phone, Outlook Web Access through the browser and now Exchange Online as a service for archival, compliance, spam filtering etc.  I was reminded by one of my team members that I owe them a blog entry while I was sitting at the airport on Tuesday.  I received that email on my Windows Mobile device.  I typed up this example using Outlook while I was flying into Vegas.  Once I get to my hotel room, I got connected and the mail was sent to some of my colleagues who are here at Vegas.  None of them need Outlook or Pocket Outlook.  Using Outlook Web Access they can use a kiosk or a public computer at the conference to read and comment on my email.  Our corporate Exchange Server which uses the Exchange Hosted spam filtering service will make sure that this is not a spam.  You get the picture.  There is a lot going on here behind the scenes where software on my laptop, on my mobile device, in the Microsoft Exchange Server and service delivered by Exchange and Exchange Hosted Service is interacting seamlessly to provide a very compelling user experience to me and my team.  It took years for the Exchange, Outlook and Exchange Hosted Services folks to build all of this.  What we are hoping to do with SQL Server, SQL Server Data Services, ADO.Net Data Services Framework and the Microsoft Synchronization Framework, is to give you, the developer a rich Data Platform to build compelling user experiences similar to the one I just described without having to spend the time and money that Microsoft has spent building Exchange, Outlook, Outlook Web Access and Exchange Only.  Your imagination should be the only limit and not the plumbing needed to tie servers software on premises, desktop software and cloud based services.

The second point is a bit tricky to make given where the service is today.  Underneath the hood, the service is running on SQL Server.  So the rich capabilities of our server software is all there.  We have chosen to expose a very simple slice of it for now.  As Nigel explained, we will be refreshing the service quite frequently as we understand our user scenarios better.  So you can expect to see more capabilities of the Data Platform to start showing up in our service over time.  What we announced here is just a starting point, our destination remains the extension of our Data Platform to the cloud.  I know you are asking "I need more details and a timeline".  As we on-board beta customers and get their feedback, we will be able to give you more details.  In the meantime,  can we agree that SSDS is simple but it is not SimpleDB.

Namashkar,
Soumitra Sengupta
Architect, SQL Server