Enumerating Large XML Files (Doug Rothaus)
How do you read an enormous XML file then? You use the XmlReader class, which has been around since the first release of the .NET Framework. It reads through an XML file, but simply places a pointer on the current XML element or attribute as you go through the file. As you read through the file with the XmlReader object, you can examine the current XML, decide if you are interested in it, process it, discard it, and move on to the next part of the file. The important thing is that you can minimize how much memory is utilized at any one time in your app.