Write large XML file non sequentially

[hamastool]

I need to write data to an XML file from C++. Each time the data changes I'll need to update two different nodes in the document.The memory needed to hold the entire document could potentially be huge so I wanted to use the stream based approach to writing an XML document. I've been looking at libxml2 and the \[code\]xmlwriter\[/code\] module. But using functions like \[code\]xmlTextWriterStartElement\[/code\] and \[code\]xmlTextWriterEndElement\[/code\] I don't think it would be possible to change two different nodes in the document each time I modify it.Essentially I can't use the DOM approach to writing the document because it could be too large to fit in memory but I need to write the document non-sequentially. Is it possible to do this?