Index: trunk/packages/sipb-xen-database/sipb_xen_database/models.py
===================================================================
--- trunk/packages/sipb-xen-database/sipb_xen_database/models.py	(revision 590)
+++ trunk/packages/sipb-xen-database/sipb_xen_database/models.py	(revision 592)
@@ -70,5 +70,5 @@
        Column('machine_id', Integer, ForeignKey('machines.machine_id'), nullable=False, index=True),
        Column('user', String, nullable=False, index=True),
-       PrimaryKeyConstraint('machine_id', 'user'))
+       PrimaryKeyConstraint('machine_id', 'user', ondelete='CASCADE'))
 
 class Machine(object):
@@ -104,5 +104,5 @@
                           'disks': relation(Disk, backref="machine", lazy=False),
                           'type': relation(Type, lazy=False),
-                          'acl': relation(MachineAccess, backref="machine", lazy=False, private=True)});
+                          'acl': relation(MachineAccess, backref="machine", lazy=False, passive_deletes=True, cascade="all, delete-orphan")});
 assign_mapper(ctx, MachineAccess, machine_access_table)
 assign_mapper(ctx, NIC, nic_table)