[hibernate-issues] [Hibernate-JIRA] Created: (HHH-2734) PreparedStatement leak with lazy properties

[Christian Gruber (JIRA)]

PreparedStatement leak with lazy properties
-------------------------------------------

                 Key: HHH-2734
                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-2734
             Project: Hibernate3
          Issue Type: Bug
          Components: core
    Affects Versions: 3.2.4
         Environment: Hibernate 3.2.4
Oracle 10g
Sun Java 1.5.0
            Reporter: Christian Gruber
            Priority: Critical


Hello!

When iterating through more than 300 elements that have lazy properties, I get an ORA-01000 JDBC error ("maximum open cursors exceeded"). I found out that the root cause for this are unclosed prepared statements in AbstractBatcher.prepareSelectStatement(String). When I add the generated prepared statement to the statementsToClose set in this method, the problem vanishes. But I don't have an idea what other effects this might have, and why the prepared statement was not added to the statements to close in the first place.

How to reproduce:

- Make a class with at least one lazy property; instrument the byte code

- Create an Oracle database with at least 300 entries in the table for this class

- Execute the following code:

Iterator<MyClass> it = session.createQuery("from MyClass mc").iterate();
while (it.hasNext()) {
    MyClass mc = it.next();
    String la = mc.getLazyAttribute();
    session.evict(mc);
}

- Watch the log for org.hibernate.jdbc.AbstractBatcher entries containing
  "about to open ResultSet" and see the numbers increase

As already mentioned, a simple fix for this is adding "statementsToClose.add( ps );" into AbstractBatcher.java, around line 133 (assigning the PreparedStatement to a new variable "ps" first, of course), but as I don't understand the differences between the various PreparedStatement generating methods there, that might give rise to other problems.

Thanks for looking at it,
Christian

-- 
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
-
For more information on JIRA, see: http://www.atlassian.com/software/jira