If you apply ACE to business partners, a few tables are generally relevant:
This is the actual Access Control List. Here, all relevant business partners are linked to an ACE-group.
One business partner can be assigned to several ace-groups.
This table will generally contain many entries (at least one for every BP).
Here, rights are mapped to actor_id’s and ACE-groups.
This table will generally not contain many entries.
The CRM_ACE2_BP_UCT contains the mapping between actual USERID’s and the ACEGROUP.