Drew,
Try this:
public void foo() {
NSArray parents;
NSArray children;
Enumeration anEnum;
EOEditingContext editingContext;
// fetch parents
anEnum = parents.objectEnumerator();
while (anEnum.hasMoreElements()) {
aParent = (Parent)anEnum.nextElement();
editingContext = new EOEditingContext();
children = fetch_with_editingContext(editingContext);
// processing...
children = null;
editingContext.dispose();
editingContext = null;
System.gc();
}
}
^James
> -----Original Message-----
> From:
> [EMAIL PROTECTED]
> ple.com
> [mailto:webobjects-dev-bounces+jcl_applewodev=dreamissary.com@
> lists.apple.com] On Behalf Of Chuck Hill
> Sent: Sunday, January 06, 2008 1:57 PM
> To: Drew Thoeni
> Cc: WebObjects-Dev List
> Subject: Re: Large Array Clogging
>
>
>
> On Jan 6, 2008, at 11:53 AM, Drew Thoeni wrote:
>
> > I have two tables in a parent-child relationship. Some of the
> > parents have a few children (say a few dozen) and others have many
> > children (over 100,000). I'm trying to run through the parents and
> > pre-calculate some statistics for their children (for example,
> > average, mode, standard deviation, etc.).
>
> I'd be tempted to take a long, hard look at some of the aggregate
> functions in Wonder that generate SQL for you. Batch processing is
> not EOF's strongest area due to the overhead of object creation and
> garbage collection.
>
>
> > All this is working except when I reach a specific parent (#457)
> > the processing just hangs. I ran this through debug and it stalls
> > at the creation of the array for the children.
> >
> > However, the system would have already processed a similar size
> > array (#30 has 118,000 children) and it seems it's in a loop.
> > Activity monitor says the java process is taking 100%.
> >
> > Other background. I only save the ec after every 20 updates to the
> > parent records (to reduce write time). And I use
> > ec.invalidateAllObjects() right after saving to clear our memory.
>
> Rather than do that, I'd create a new EC and just not retain _any_
> references to the objects previously processed, the previous
> EC etc.
> EOF snapshot counting and Java GC should take care of the rest.
>
>
> > Finally, there is nothing wrong with the data in parent/children of
> > #457 as I can start the process there (or a few parents ahead of
> > this) and it runs fine.
> >
> > This seems like a memory problem, but I don't get an out of memory
> > exception.
>
> Before OutOfMemory, there is memory starvation. I think that
> is what
> is happening to you. Increase the heap size and see if that delays
> the problem to a later parent. You could also launch with a JVM
> parameter of -verbose:gc to log when GC happens.
>
> The solution is to clean up your handling of objects and editing
> contexts.
>
> Chuck
>
> --
>
> Practical WebObjects - for developers who want to increase their
> overall knowledge of WebObjects or who are trying to solve specific
> problems. http://www.global-village.net/products/practical_webobjects
>
>
>
>
>
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