Are there any production-ready libraries for streaming XPath expressions evaluation against provided xml-document? My investigations show that most of existing solutions loa
There are several options:
DataDirect Technologies sells an XQuery implementation that employs projection and streaming, where possible. It can handle files into the multi-gigabyte range - e.g. larger than available memory. It's a thread-safe library, so it's easy to integrate. Java-only.
Saxon is an open-source version, with a modestly-priced more expensive cousin, which will do streaming in some contexts. Java, but with a .net port also.
MarkLogic and eXist are XML databases that, if your XML is loaded into them, will process XPaths in a fairly intelligent fashion.