A database system receives a transaction that causes a tuple to be
integrated into a join view. In response to receiving the transaction, a
predefined first lock is placed on at least a portion of the join view,
the predefined first lock conflicting with either a shared lock or an
exclusive lock placed on the join view, but not conflicting with another
predefined first lock placed on the join view. Also, a latch or semaphore
associated with a value of a predetermined attribute of the tuple is
obtained before integrating the tuple into the join view.