Summary: Transactional Contention Management
as a Non-Clairvoyant Scheduling Problem
February 26, 2007
The transactional approach to contention management guarantees atomicity by mak-
ing sure that whenever two transactions have a conflict on a resource, only one of them
proceeds. A major challenge in implementing this approach lies in guaranteeing progress,
since transactions are often restarted.
Inspired by the paradigm of non-clairvoyant job scheduling, we analyze the performance
of a contention manager by comparison with an optimal, clairvoyant contention manager
that knows the list of resource accesses that will be performed by each transaction, as
well as its release time and duration. The realistic, non-clairvoyant contention manager is
evaluated by the competitive ratio between the last completion time (makespan) it provides
and the makespan provided by an optimal contention manager.
Assuming that the amount of exclusive accesses to the resources is non-negligible, we
present a simple proof that every work conserving contention manager guaranteeing the