[TYPO3-english] Bidirectional 1:n relations over several tables - better prevent them?

[Jan Kornblum]

Dear newsgroup,

i am currently working on an extension having bidirectional 1:n and n:1 
relations over 3 tables: A <-1:n-> B <-n:1-> C (There are about 120 
A-Records, 800 B-Records and 20 C-Records).

Independent from some extbase performance issues, there are problems 
regarding the handling of these records in the backend:

For example, when i try to copy a sysfolder containing the records, the 
memory limit exceeds (although i've tried to increase it to nearly 
1GB!) because the records are copied recursively.

The same happens when i try to do a t3d-export of a sysfolder 
containing these records. It is impossible.

So i've got the following questions:

- Should bidirectional relations better be prevented because the 
backend / tca isn't able to handle this?

- Is there any setting to prevent copying of related records / child 
records for certain tables / at all when using the list module?

I would be very glad if anybody could give me an advise about this...

Kind regards, Jan