Regarding XML databases, there is an excellent open-source XML database 'eXist' which currently uses indexes to speed up both structure-based and content-based retrieval via XQuery; there are plans on their development roadmap to replace parts of the indexing mechanism, particularly fulltext analysis, with components from Lucene... intriguing, but I expect that will take awhile.
http://exist.sourceforge.net/roadmap.html - J.J. At 1:03 PM -0700 9/22/06, Walter Underwood wrote: >There is one product that does transactional query and text >search: MarkLogic. It does a good job of both, but it is very >XML-centric. It might be a good match, if you are into commercial >software. It is a rather different style of programming than >SQL or Lucene. You write XQuery to define the result XML with >the contents fetched from the database.
