hi there-  I have a data-oriented XML schema db that contains mostly scheduling information.. I have attempted to use javax.xml.* library to query the db, with abysmal performance.      statements such as  xpath.evaluate(doc,"//sdp:service//sdp:trip) or even the pre-compiled version  xexpr.evaluate(nodelist)     are an order slower than the DOM call getTagByName("trip").     don't even get me started on queries like "//sdp:service//sdp:trip[id='1'][type='north']"        I see there are many xpath enabled libraries.. is there one in which xpath utilization is much faster? at least on par with the DOM calls? I've looked on the web and it seems that query processing optimizaiton is an academic pursuit of it's own...     Should I rather be using DOM's new implementation of
 XPath ?  should I be using an RDBMS rather than an xml db at all if query performance is going to be so slow?   many questions..  I am planning to do some additional benchmarking, but I'd rather not re-invent the wheel... If someone could point me to an old post or even better  answer my primary question directly, that would be great.  thanks,  Cindy