Observations on optimistic concurrency control schemes
نویسنده
چکیده
Attstraet-Gptimistic concurrency control schemes allow uncontrolled access to shared data objects during transaction processing under the explicit assumption that read and write coticts among transactions are rare events. Before a transaction commits, the DBMS has to validate that no conflict has occurred Conflict resolution mainly relies on transaction abort. Two different optimistic concurrency control schemes are introduced and compared to each other. The problems of implementing such schemes and their implications on DBMS processing is investigated in some detail. A number of general properties of optimistic concurrency control schemes is derived, and their advantages and drawbacks w.r.t. two-phase locking approaches are discussed.
منابع مشابه
Experimental Evaluation of Real-Time Optimistic Concurrency Control Schemes
Due to its potential for a high degree of parallelism, optimistic concurrency control is expected to perform better than two-phase locking when integrated with priority-driven CPU scheduling in real-time database systems. In this paper, we examine the overall effects and the impact of the overheads involved in implementing real-time optimistic concurrency control. Using a locking mechanism to e...
متن کاملOptimistic Concurrency Control based on Cache Coherency in Distributed Database Systems
Optimistic concurrency control highly takes advantage of parallelism because there is no delay by lock. Unfortunately, I/O operations by transactions and cache operations are delayed in the optimistic concurrency control. In order to reduce such delay, we combine cache coherency control and optimistic concurrency control rather than they operate in separate. In this paper, we propose optimistic...
متن کاملThe glass is half full On the application of an optimistic approach to concurrency control schemes Dominik Moritz
متن کامل
Mostly-Optimistic Concurrency Control for Highly Contended Dynamic Workloads on a Thousand Cores
Future servers will be equipped with thousands of CPU cores and deep memory hierarchies. Traditional concurrency control (CC) schemes -both optimistic and pessimistic -slow down orders of magnitude in such environments for highly contended workloads. Optimistic CC (OCC) scales the best for workloads with few conflicts, but suffers from clobbered reads for high conflict workloads. Although pessi...
متن کاملOptimistic replication in HOPE
The growing imbalance between network latency and throughput is causing nodes in distributed systems to appear to be moving farther apart. Many distributed systems are turning to replication as a mechanism to make resources appear closer. However, maintaining one-copy consistency in a system containing replicated elements has proven diicult. In particular, the checks required to make consistent...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Inf. Syst.
دوره 9 شماره
صفحات -
تاریخ انتشار 1984