Data replication is an approach which is supposed to increase data availability. Especially in mobile networks the availability can become a serious problem. In this paper we present our research on which nodes of VAN...
详细信息
Caching frequently asked queries is an effective way to improve the performance of both centralized and distributed database systems. Intensive works have been done in this area to propose different query caching tech...
详细信息
Caching frequently asked queries is an effective way to improve the performance of both centralized and distributed database systems. Intensive works have been done in this area to propose different query caching techniques and to evaluate their performance. However, most of these works were confined to caching previous query results in a single-level caching architecture. Evaluations of these works were based on simulations. In [1], we proposed a new query caching technique for caching both query results and execution plans in a multi-level caching architecture. The centralized version of this technique was evaluated and the results were reported in [2]. In this paper, we present an analytical model to evaluate the performance of the proposed technique in distributed database systems.
Data replication is an approach which is supposed to increase data availability in mobile networks, especially in the networks of VANET type (vehicle ad-hoc networks). In this work we present our solution for data dis...
详细信息
The provision of access to autonomous heterogeneous distributed information sources (including databases) is becoming of increasing importance in most aspects of daily life. It has been the subject of intensive resear...
详细信息
We propose an inference prevention agent as a tool that enables each of the databases in a distributed system to keep track of probabilistic dependencies with other databases and then use that information to help pres...
详细信息
ISBN:
(纸本)0769518494
We propose an inference prevention agent as a tool that enables each of the databases in a distributed system to keep track of probabilistic dependencies with other databases and then use that information to help preserve the confidentiality of sensitive data. This is accomplished with minimal sacrifice of the performance and survivability gains that are associated with distributed database systems.
Traditional protocols for distributeddatabase management have high message overhead, lock or restrain access to resources during protocol execution, and may become impractical for some scenarios like real-time system...
详细信息
Data Fragments Allocation is an important issue in designing distributeddatabase System. This problem is NP*complete, and thus requires fast heuristics and random algorithms to generate efficient solutions, so many a...
详细信息
In this paper, a new replica control algorithm, called the multiple tree quorum (MTQ) algorithm, is proposed to manage replicated data in distributed database systems. This algorithm provides a high availability for r...
详细信息
In this paper, we consider parallel execution of chain queries in distributeddatabase environments. The general scheme we propose is to assign to each processing site a fragment of each relation referenced by the que...
详细信息
ISBN:
(纸本)0897916344
In this paper, we consider parallel execution of chain queries in distributeddatabase environments. The general scheme we propose is to assign to each processing site a fragment of each relation referenced by the query. Each site executes the joins of the fragments of the relations autonomously. The answer to the query is the union of the partial results generated by the processing sites. We derive the size of each fragment of each relation assigned to a site which yields the minimum amount of data distributed to each site. It is shown that this performs significantly better than a straight forward scheme in which two relations referenced by the query are completely partitioned and the remaining relations are replicated at exact processing site.
Most of previous studies on automatic database partitioning focus on deriving a (near-)optimal (re)partition scheme according to a specific pair of database and query workload and oversees the problem about how to eff...
详细信息
暂无评论