Can I enforce the order of XML attributes using a schema?

Question

Our C++ application reads configuration data from XML files that look something like this:

Answer 1

As others have pointed out, no, you can't rely on attribute ordering.

If I had any process at all involving 2,500 XML files and 1.5 million key/value pairs, I would get that data out of XML and into a more usable form as soon as I possibly could. A database, a binary serialization format, whatever. You're not getting any advantage out of using XML (other than schema validation). I'd update my store every time I got a new XML file, and take parsing 1.5 million XML elements out of the main flow of my process.