Multilevel Categorization with million of subcategories

Dear experts,

using the SAP CRM Web UI 7.40 with the role IC Service Manager, is it possible to implement a multilevel categorization scheme with about 25.000.000 to 250.000.000 subcategories?

When we implement the given categorization, the system dumps with the exception of "SYSTEM OUT OF MEMORY" in the transaction ST22.

Are there a workaround for this issue?

Thanks in advance

Enrico