[TYPO3-mvc] ObjectStorage with large quantities of DB-Objects

[Nils Blattner]

Hi there

We currently have a running project with 4000 odd fe_users and an 
extension specific table with something around 50000 records spread 
around all the fe_users.

For an export (xml-xls) in the backend I have to go through all of them.
Now with these kinds of numbers, memory consumption is going through the 
roof.
In the actual code I cannot find any arrays that still store the users + 
records attached and I remove the references as soon as I use them.
So I suspect because Extbase (Backend session specifically) stores the 
objects the script can't free the memory and crashes.
I tried to remove the extbase references with
$session->unregisterReconstitutedObject($user);
where $session is the session of the persistence manager.

Any ideas or extbase ways how to solve this problem?
Increasing the memory limit is not that good an option either, because 
we expect to have something around 150k rows by the end of the project :=)

Regards

Nils