Malte,
What exactly would you change?
The unique constraint is because of an index on (context_id,object_id).
Or rather the other way around.
"
-- The unique constriant about will force create of this index...
-- create index acs_objects_context_object_idx onacs_objects (context_id, object_id);
"
Point is, we can't change this, and I can't imagine why you would want to. What sort of transactions are failing due to this constraint? An example would be helpful.