How to use Xpath to query elements loaded from different xml docs?

Question

I have a big DBLP XML doc (95mb), to load into the container, i splitted the doc into many small xml docs by the publication types, such as articles, books, inproceedings, etc.
I tried to use xpath query such as
query 'collection()/dblp[article/author]/book[title]'
I got empty answers.
but if i use XQuery such as
query 'let $r:=collection()/dblp,$a :=$r/inproceedings/author
for $l2 in $r/book
where $a and $l2/title
return <result> {$l2}{$a}</result>'
i got answers. However, if i remove {$a} from the return clause, i still got empty answers.
is there any problem with my Xpath query and flwor Xquery?
regards,
xiaoying

Answer 1

Hi John,
Following is the procedure i have used to load the xml docs (after the indexes have been created):
private static void loadXmlFiles(File path2DbEnv,String theContainer, File file) throws Throwable {
     //Open a container in the db environment
          XmlManager theMgr = null;
          XmlContainer openedContainer = null;
          myDbEnv env;
          try {
          env = new myDbEnv(path2DbEnv);
     theMgr = new XmlManager(env.getEnvironment(), new XmlManagerConfig());
     //use node container
     theMgr.setDefaultContainerType(XmlContainer.NodeContainer);
               try{
               openedContainer = theMgr.createContainer(theContainer);
               }catch (XmlException e){
                    //if the container alreay exist, then open it;     
                    openedContainer = theMgr.openContainer(theContainer);
          //Get an update context.
          XmlUpdateContext updateContext = theMgr.createUpdateContext();
               String theFile = file.toString();
               String docName=file.getName();
          //Get the input stream.
          XmlInputStream theStream = theMgr.createLocalFileInputStream(theFile);
          System.out.println("Adding " + theFile + " to container " +
                         theContainer);
     //     Do the actual put
          openedContainer.putDocument(docName, // The document's name
          theStream, // The actual document.
          updateContext, // The update context
     //     (required).
          null); // XmlDocumentConfig object
          System.out.println("done.");
          //XmlException extends DatabaseException, which in turn extends Exception.
          // Catching Exception catches them all.
          } catch (XmlException e){
               System.err.println("Error loading files into container " + theContainer);
               System.err.println(" Message: " + e.getMessage());
               //In the event of an error, we abort the operation
               // The database is left in the same state as it was in before
               // we started this operation.
               throw e;
          finally {
          cleanup(theMgr, openedContainer);
Unfortunately, i waited for around 20 hours 148mb doc was not loaded; so i gave up.
Could you please give me some suggestions on how to load the large doc efficiently ? thanks.
regards,
xiaoying