Why the Database as a Service is a Bad Idea

Microsoft recently released SP1 for .NET. While the SP brings some nice stuff, it seems it also has some bugs and a few less than inspiring components.

Another example for a less than stellar idea is the "ADO.NET data services" component. Before I go on to explain why I think that, I should probably mention that this isn't just a Microsoft thing as IBM also mentions similar ideas as part of their (broader and sometimes even worse) view of "Information as a Service".

So why is exposing the database through a web-service (RESTful or otherwise) wrong? Let me count the ways:

1. It circumvents the whole idea about "Services" - there's no business logic
2. It makes for CRUD resources/services
3. It is exposing internal database structure or data rather than a thought-out contract
4. It encourages bypassing real services and going straight to their data
5. It creates a blob service (the data source)
6. It encourages minuscule demi-serices (the multiple "interfaces" of said blob) that disregard few of the fallacies of distributed computing
7. It is just client-server in sheep's clothing

When it comes for ADO.NET data services you can add a few other problems like:

1. it isn't really RESTful - you can also "enhance" the services with operations like example 18 in "Using ADO.NET data services" : http://host/vdir/northwind.svc/CustomersByCity?city=London (though it does support caching and hypermedia ). Not being only RESTful is not a bad thing in itself. It is the inconsistency of the API when the reson de etre of the service is exposing data
2. Also (on not being RESTful) it doesn't really externalize a state machine it externalizes a relational model
3. It is built on Entity Services.

VP R&D of xsights (www.xsights.com) Arnon Rotem Gal-Oz has more than 19 years of experience managing, architecting and building large scale, mission critical, distributed systems. Before joining XSIGHTS, Arnon worked as the development manager of the Biometrics line in Rafael. Prior to that, he worked in various technical and managerial roles in large corporations including Microsoft, Amdocs and Matrix. Arnon is a DZone MVB and is not an employee of DZone and has posted 25 posts at DZone.