[Hibernate-issues] [Hibernate-JIRA] Updated: (HB-483) Odd behavior from query cache startup

[<leg...@at...>]

The following issue has been updated:

    Updater: Loren Rosen (mailto:lor...@ma...)
       Date: Fri, 21 Nov 2003 11:39 AM
    Comment:
annotated debug log file
    Changes:
             Attachment changed to a.txt
    ---------------------------------------------------------------------
For a full history of the issue, see:

  http://opensource.atlassian.com/projects/hibernate/secure/ViewIssue.jspa?key=HB-483&page=history

---------------------------------------------------------------------
View the issue:

  http://opensource.atlassian.com/projects/hibernate/secure/ViewIssue.jspa?key=HB-483


Here is an overview of the issue:
---------------------------------------------------------------------
        Key: HB-483
    Summary: Odd behavior from query cache startup
       Type: Bug

     Status: Unassigned
   Priority: Minor

    Project: Hibernate2
 Components: 
             core
   Versions:
             2.1 beta 6

   Assignee: 
   Reporter: Loren Rosen

    Created: Thu, 20 Nov 2003 12:16 PM
    Updated: Fri, 21 Nov 2003 11:39 AM
Environment: Mac OSX 10.1.5
JDK 1.3.1

Description:
It seems that it takes 3 query calls before the query cache is propery initialized and starts caching queries. I'll grant this isn't so critical for overall effectiveness of the cache, but it will confuse someone who tries to write a very simple program to demonstrate the operation of the query cache.

For example, if the gist of main() is this:
        Session sess;
        Long l = new Long(79);

        for (int i=1;i<=5;i++) {
            System.out.println("-----run query iteration " + i + " --------------");
            sess = sessions.openSession();
            runQuery(l, sess);
            sess.close();
        }

and here's the method it calls
    private static void runQuery(Long docId, Session sess) throws Exception {

        Document doc;
        Transaction tx = null;

        try {
            tx = sess.beginTransaction();
            Query q = sess.createQuery("select from Document doc where doc.id=:docId");
            q.setLong("docId", docId.longValue());
            q.setCacheable(true);
            List list = q.list();
            tx.commit();
        } catch (Exception e) {
            tx.rollback();
            throw e;
        }

    }

If you run this with query logging enabled, you'll see that only the 4th and 5th iterations of loop succeed in getting the query results from the query cache.

I've traced through the code, and I think I know what's going on. It's a bit complicated to explain, but I'll be happy to write it down if anyone wants to try fixing the problem.


---------------------------------------------------------------------
JIRA INFORMATION:
This message is automatically generated by JIRA.

If you think it was sent incorrectly contact one of the administrators:
   http://opensource.atlassian.com/projects/hibernate/secure/Administrators.jspa

If you want more information on JIRA, or have a bug to report see:
   http://www.atlassian.com/software/jira