XmlQueryExpression on windows system.

Question

Hi, everyone
I have a question about XmlQueryExpression::execute() function.
If I use dbxml>query 'collection()/SR\[StartTime > 100000\]' ,
it only took 1156ms to return 20000 docs.
but if I used my code to execute the query ,the XmlQueryExpression::execute() function took about 8s(only the function cost!).
I do not known why,here is my environment info and code.
My environment info:
Version: Oracle: Berkeley DB XML 2.4.13: (April 29, 2008)
Berkeley DB 4.6.21: (September 27, 2007)
No default container
Shell and XmlManager state:
Not transactional
Verbose: on
Query context state: LiveValues,Eager
My system is windows xp sp2,compiler is vc8.
Here is my intput code:
std::string containerPath = "C:\\BDBXML\\test.dbxml";
XmlManager mgr;
XmlContainer cont = NULL;
if(mgr.existsContainer(containerPath) == 0)
cont = mgr.createContainer(containerPath);
else
cont = mgr.openContainer(containerPath);
ShowTime("Write 20000 docs Start:");
XmlUpdateContext uc = mgr.createUpdateContext();
for(int i = 0;i<20000;i++)
XmlDocument doc = mgr.createDocument();
XmlEventWriter &writer = cont.putDocumentAsEventWriter(doc, uc,DBXML_GEN_NAME);
writer.writeStartDocument(NULL, NULL, NULL);
writer.writeStartElement((const unsigned char *)"SR",NULL,NULL,0,false);
writer.writeStartElement((const unsigned char *)"StartTime",NULL,NULL,0,false);
writer.writeText(XmlEventReader::Characters, (const unsigned char *)"1221032389", 10);
writer.writeEndElement((const unsigned char *)"StartTime", NULL, NULL);
writer.writeEndDocument();
writer.close();
ShowTime("Write 20000 docs End:");
cont.sync();
Here is my query code:
std::string containerPath = "C:\\BDBXML\\test.dbxml";
XmlManager mgr;
XmlContainer cont;
if(mgr.existsContainer(containerPath) == 0)
cont = mgr.createContainer(containerPath);
else
cont = mgr.openContainer(containerPath);
cont.addAlias("test.dbxml");
XmlQueryContext context = mgr.createQueryContext();
std::string myQuery = "collection('test.dbxml')/SR\[StartTime >100000\]";
XmlQueryExpression qe = mgr.prepare(myQuery, context);
ShowTime("Eager Search Start:");
XmlResults results = qe.execute(context);
ShowTime("Eager Search End:");
XmlValue value;
int count = 0;
while (results.next(value))
count++;
std::cout<<"The Doc Num is "<<count<<std::endl;
Edited by: user608958 on 2008-9-12 上午2:17

Answer 1

The problem has been solved,thank you rucong.zhao!
My old app version and old bdb xml lib version was all debug ,the performance was bad.
I ran the realse version in the vs2005 and it improved a little.
Input took 5s;
Query took 8s;
But if I run the test.exe(not in vs2005 environment) directly,everything is good!
Input took 3s;
Query took 1s around;
I think it is just the vs2005 version problem(or compiler optimize options),though I still not understanded the debug version's efficiency.