Monthly Archives: March 2012

Layers of Abstraction

One of the questions I often hear when I tell someone that I work on ADO.NET is “Is that still alive?” And, while ADO may be long gone, ADO.NET is today one of the most popular ways to connect to SQL Server and is the underlying layer beneath many (if not all) .Net Object Relational Mappers (ORMs) like Entity Framework (EF). However, it is because of these ORMs that you never hear about ADO.NET – it is no longer the “new, sexy” thing (and we don’t have product names like “Magical Unicorn Edition”). This does not mean that ADO.NET is simply becoming a framework to build ORMs, the world is a bit more complicated than that…

One thing that ORMs do well is to allow developers to quickly and easily get a database up and running, and then to get access to the data that is sitting there. For instance, the tooling in EF allows you to quickly create a model, deploy that to a database, code some LINQ (with its IntelliSense goodness) to grab some data, and then manipulate that data as an object. ORMs also make prototyping and rapid development easier as the model they generate can be updated from the database and any changes in the database schema will then show as compiler errors since the corresponding object in that model has now changed as well. One of the problems with EF, and ORMs in general, is that the extra layer of abstraction adds a performance cost, and while EF has been working to reduce that, you can see from the graph below that hand-coded ADO.NET is vastly quicker – so, what to do?

Opportunity Cost

As with any technology choice, you need to carefully considered what each option offers, and what each options costs. EF (and ORMs) offer quick and easy coding at the cost of the application’s performance. For some projects this may be fine – the developers may be too busy to consider hand-coding, or the cost of additional servers may be much less that finding, hiring and onboarding additional developers. Alternatively, ADO.NET may be chosen if the application is large enough that any percentage performance increase is a significant cost savings, or that the turn around time for a single database transaction is critical and every microsecond counts. Just to emphasize the point – remember that ADO.NET is an abstraction from the TDS protocol. There may be developers for which they performance is ultra-critical and they would rather hand-code TDS packets and communicate with SQL Server that way (which is entirely possible, since TDS is a documented protocol).

At the end of the day, you need to choose what makes sense to you and to your business plan – whether that means hand-coding ADO.NET, utilizing an ORM or a mix in between (like starting with an ORM and then hand-coding performance critical queries).

(As a side note: .Net 4.5 Beta has arrived! And ADO.NET has some new features that I will be posting about soon – in the meantime download the Beta and get coding, and be sure to log any bugs or suggestions on the Connect site or the Forums)

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