I can't imagine why that would happen. If this was a bug, I would think far
more people would be experiencing it. I have apps that have run for months,
and in some cases years, without running out of memory. GroupBy doesn't do
anything special really. It just skips duplicate rows for a parent class.
Try iBATIS 2.3.1. If there is a problem, it might have to do with
session/transaction management. 2.3.1 improves the handling of such.
Clinton
On Fri, Apr 11, 2008 at 10:10 AM, Harvey Kim <[EMAIL PROTECTED]> wrote:
> If you use groupBy, you will eventually run out of memory. Few months
> ago, I e-mailed a sample program which showed my application doing
> absolute nothing except issuing a ibatis query. It was using
> queryWithRowHandler. Literally, all it did was call
> "queryWithRowHandler" and my rowHanlder did absolutely nothing.
> Literally this:
>
> public class IbatisDownloadThread implements Runnable, Serializable,
> RowHandler
> {
> private SqlMapClient sqlMapClient = null;
>
> public void run()
> {
> try
> {
> sqlMapClient = BaseDAO.getSqlMapClient();
> sqlMapClient.queryWithRowHandler("getIdList", queryDto, this);
> }
> }
>
> public void handleRow()
> {
> }
> }
>
> The above code eventually gets "Out of Memory" error and the query is
> using a groupBy. When I took out the "groupBy", it went MUCH MUCH MUCH
> longer. But even that ran out of memory after few hours of running.
> However, once I converted everything to a JDBC loop, "Out of Memory"
> error went away. When I examined the available memory at runtime, I
> could see the available memory decreasing with every call to
> "handleRow()". With JDBC, I examined the heap size inside the loop and
> it held steady for hours and finished without a problem.
>
> The moral of the story - you could probably get away with ibatis if you
> take out the groupBy (that was my quick fix). I took out the groupBy
> and simply issued another ibatis command to get the list inside
> "handleRow()". That was my quick fix and it is probably sufficient for
> now.
>
> You can still run out of memory if you use "queryWithRowHandler" but
> highly unlikely unless you have an application like mine which could
> have a thread running for days. But to be really safe, you have to go
> back to JDBC. Since I was on a tight deadline, I didn't bother going
> through the ibatis code but I may do that one of these days because it
> is a wonderful tool.
>
>
> On Tue, 8 Apr 2008 12:27:29 -0700 (PDT), "Carlos de Luna Saenz"
> <[EMAIL PROTECTED]> said:
> > It seems like there is not enough data in your mail...
> > what data base are you accessing? how are you dealing with it
> (DataSource
> > is JDBC or via the App Server) your class is keeping the data for any
> > reason (maybe in a session or application bean)? what's the App Server?
> > etc, etc... if i were you i should look all that kind of variables and
> > monitor with a profiler to see if there's somehint wrong with the query,
> > the server, the managed memory, or all of the above.
> > Greetings
> > Carlos de Luna
> >
> > ----- Mensaje original ----
> > De: Fernando Simonetti <[EMAIL PROTECTED]>
> > Para: "[email protected]" <[email protected]>
> > Enviado: martes, 8 de abril, 2008 7:51:26
> > Asunto: groupby x out of memory
> >
> > Eventually my aplication server is going down by "Out of Memory".
> > Analizing
> > de heap dumping, it's point for the same class allocating 600 Mb.
> >
> > This event can occur 3 hours or 3 days after I restart my server. This
> > class
> > is used thounsands times in the period. Monitoring the memory of the
> > server,
> > I could see 300MB to 700MB of memory been allocated in 3 minutes. It
> > hapens
> > eventualy but not in a determined period.
> >
> > The unique diference for this class for others, is the groupby clause in
> > Ibatis. First I thouth it could be a cartesian product, but I ran the
> > query
> > without parameters and found nothing.
> >
> > I going to implement this class without groupby clause, but first I
> would
> > like to see if there are other options.
> >
> >
> > thanks,
> > Fernando
> >
> >
> >
> ____________________________________________________________________________________
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