Dozens of articles have been published describing "new" concurrency control algorithms for distributed database systems. All of these algorithms can be derived and understood using a few basic concepts. We show how to decompose the concurrency control problem into several subproblems, each of which has iust a few known solutions. By appropriately combining known solutions to the subproblems, we...

Use of transactional multicore main-memory databases is growing due to dramatic increases in memory size and CPU cores available for a single machine. To leverage these resources, recent concurrency control protocols have been proposed for main-memory databases, but are largely optimized for specific workloads. Due to shifting and unknown access patterns, workloads may change and one specific a...

This paper presents a technique that is capable of supporting four major requirements for concurrency control in real-time databases: transaction temporal consistency, transaction logical consistency, data temporal consistency, and data logical consistency, as well as tradeoos among these four requirements. The technique is based upon an object-oriented real-time database model in which each ob...

In object oriented distributed systems (OODS), the objects are viewed as resources. Concurrency control techniques are usually applied on the database tier. This has the limitations of lack of support of legacy files and requirement of separate concurrency control mechanisms for each database model. Hence concurrency control on the objects at server tier is explored. To implement concurrency co...

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...

Concurrency control is important for multilevel secure databases because a covert channel can be easily created through collaboration of multilevel transactions in most traditional concurrency control mechanisms. We, in this paper, propose a secure multiversion concurrency control mechanism. We present concepts of an invisible area and a t-lock to prevent retrieval anomaly and starvation of hig...

Transaction management comprises diierent aspects such as concurrency control, recovery control, and replication control. Usually, only one or at least two of these aspects are considered in theories of transaction management|the other aspects are ignored. In this paper, we propose a model of executions that allows to capture all three aspects of transaction management. Based on this execution ...

The goal of concurrency control is to guarantee the correct interleaving of the operations. ROLL (Request Order Linked List) is a concurrency control method which can avoid transaction abort and minimize transaction restart. In its basic form, it requires predeclaration before a transaction is scheduled, similar to other conservative concurrency control methods, including conservative 2PL (2-Ph...

Developing concurrent applications is not a trivial task. As programs grow larger and become more complex, advanced concurrency control mechanisms are needed to ensure that application consistency is not compromised. Managing mutual exclusion on a per-object basis is not sufficient to guarantee isolation of sets of semantically-related actions. In this paper, we consider ‘atomic blocks’, a simp...

The granularity of concurrency control has a big impact on the performance of transactional systems. Concurrency control granularity and data granularity (data size) are usually the same. The e ect of this coupling is that if a coarse granularity is used, the overhead of data access (number of disk accesses) is reduced, but also the degree of concurrency. On the other hand, if a ne granularity ...