Modern database systems desperate for the ability to support highly scalable transactions and efficient queries simultaneously for real-time applications.One solution is to utilize query optimization techniques on the...Modern database systems desperate for the ability to support highly scalable transactions and efficient queries simultaneously for real-time applications.One solution is to utilize query optimization techniques on the on-line transaction processing(OLTP)systems.The materialized view is considered as a panacea to decrease query latency.However,it also involves the significant cost of maintenance which trades away transaction performance.In this paper,we examine the design space and conclude several design features for the implementation of a view on a distributed log-structured merge-tree(LSMtree),which is a well-known structure for improving data write performance.As a result,we develop two incremental view maintenance(IVM)approaches on LSM-tree.One avoids join computation in view maintenance transactions.Another with two optimizations is proposed to decouple the view maintenance with the transaction process.Under the asynchronous update,we also provide consistency queries for views.Experiments on TPC-H benchmark show our methods achieve better performance than straightforward methods on different workloads.展开更多
Many proposed P2P networks are based on traditional interconnection topologies. Given a static topology, the maintenance mechanism for node join/departure is critical to designing an efficient P2P network. Kautz graph...Many proposed P2P networks are based on traditional interconnection topologies. Given a static topology, the maintenance mechanism for node join/departure is critical to designing an efficient P2P network. Kautz graphs have many good properties such as constant degree, low congestion and optimal diameter. Due to the complexity in topology maintenance, however, to date there have been no effective P2P networks that are proposed based on Kautz graphs with base ~ 2. To address this problem, this paper presents the ＂distributed Kautz （D-Kautz） graphs＂, which adapt Kautz graphs to the characteristics of P2P networks. Using the D-Kautz graphs we further propose SKY, the first effective P2P network based on Kautz graphs with arbitrary base. The effectiveness of SKY is demonstrated through analysis and simulations.展开更多
Update management is very important for data integration systems. So update management in peer data management systems （PDMSs） is a hot research area. This paper researches on view maintenance in PDMSs. First, the d...Update management is very important for data integration systems. So update management in peer data management systems （PDMSs） is a hot research area. This paper researches on view maintenance in PDMSs. First, the definition of view is extended and the peer view, local view and global view are proposed according to the requirements of applications. There are two main factors to influence materialized views in PDMSs. One is that schema mappings between peers are changed, and the other is that peers update their data. Based on the requirements, this paper proposes an algorithm called 2DCMA, which includes two sub-algorithms： data and definition consistency maintenance algorithm% to effectively maintain views. For data consistency maintenance, Mork＇s rules are extended for governing the use of updategrams and boosters. The new rule system can be used to optimize the execution plan. And are extended for the data consistency maintenance algorithm is based on the new rule system. Furthermore, an ECA rule is adopted for definition consistency maintenance. Finally, extensive simulation experiments are conducted in SPDMS. The simulation results show that the 2DCMA algorithm has better performance than that of Mork＇s when maintaining data consistency. And the 2DCMA algorithm has better performance than that of centralized view maintenance algorithm when maintaining definition consistency.展开更多
Real-time collaborative editing(RTCE)can support a group of people collaboratively work from distributed locations at the same time.However,consistency maintenance is one key challenge when different types of conflict...Real-time collaborative editing(RTCE)can support a group of people collaboratively work from distributed locations at the same time.However,consistency maintenance is one key challenge when different types of conflicts happen.Therefore a common synchronous mechanism is proposed to support consistency maintenance in the process of multi-view business modeling.Based on operation analysis on different views of models in the real-time collaborative editing system,detection of potential conflicts is realized by means of a decision-making tree.Then consistency maintenance provides a comprehensive and applicable conflicts detection and resolution for collaborative business modeling.Finally,a prototype of collaborative multi-view business modeling system is introduced to verify the approach.The point is that the mechanism proposes a comprehensive solution for collaborative multi-view business modeling.展开更多
提出了一种版本控制集合刷新算法 ( V SR A) .它采用增量维护、版本控制和批处理机制保证数据仓库的联机维护和数据一致性 .V SRA不仅减少了数据库和数据仓库之间的通信流量 ,而且提高了实体化视图的刷新效率 .用户可以随时使用 V SRA...提出了一种版本控制集合刷新算法 ( V SR A) .它采用增量维护、版本控制和批处理机制保证数据仓库的联机维护和数据一致性 .V SRA不仅减少了数据库和数据仓库之间的通信流量 ,而且提高了实体化视图的刷新效率 .用户可以随时使用 V SRA进行联机分析处理 。展开更多
基金This work was partially supported by Youth Foundation of National Science Foundation(61702189)National Science Foundation(61772202).
文摘Modern database systems desperate for the ability to support highly scalable transactions and efficient queries simultaneously for real-time applications.One solution is to utilize query optimization techniques on the on-line transaction processing(OLTP)systems.The materialized view is considered as a panacea to decrease query latency.However,it also involves the significant cost of maintenance which trades away transaction performance.In this paper,we examine the design space and conclude several design features for the implementation of a view on a distributed log-structured merge-tree(LSMtree),which is a well-known structure for improving data write performance.As a result,we develop two incremental view maintenance(IVM)approaches on LSM-tree.One avoids join computation in view maintenance transactions.Another with two optimizations is proposed to decouple the view maintenance with the transaction process.Under the asynchronous update,we also provide consistency queries for views.Experiments on TPC-H benchmark show our methods achieve better performance than straightforward methods on different workloads.
基金Supported partially by the National Natural Science Foundation of China (Grant Nos. 60673167 and 60703072)the Hunan Provincial Natural Science Foundation of China (Grant No. 08JJ3125)the National Basic Research Program of China (973) (Grant No. 2005CB321801)
文摘Many proposed P2P networks are based on traditional interconnection topologies. Given a static topology, the maintenance mechanism for node join/departure is critical to designing an efficient P2P network. Kautz graphs have many good properties such as constant degree, low congestion and optimal diameter. Due to the complexity in topology maintenance, however, to date there have been no effective P2P networks that are proposed based on Kautz graphs with base ~ 2. To address this problem, this paper presents the ＂distributed Kautz （D-Kautz） graphs＂, which adapt Kautz graphs to the characteristics of P2P networks. Using the D-Kautz graphs we further propose SKY, the first effective P2P network based on Kautz graphs with arbitrary base. The effectiveness of SKY is demonstrated through analysis and simulations.
基金This work is supported by the National Natural Science Foundation of China under Grant Nos. 60503038, 60473069, 60496325 and 60573092. The authors would like to thank Peter Mork for his comments on the extended rule system, and also thank the anonymous referees for their invaluable comments.
文摘Update management is very important for data integration systems. So update management in peer data management systems （PDMSs） is a hot research area. This paper researches on view maintenance in PDMSs. First, the definition of view is extended and the peer view, local view and global view are proposed according to the requirements of applications. There are two main factors to influence materialized views in PDMSs. One is that schema mappings between peers are changed, and the other is that peers update their data. Based on the requirements, this paper proposes an algorithm called 2DCMA, which includes two sub-algorithms： data and definition consistency maintenance algorithm% to effectively maintain views. For data consistency maintenance, Mork＇s rules are extended for governing the use of updategrams and boosters. The new rule system can be used to optimize the execution plan. And are extended for the data consistency maintenance algorithm is based on the new rule system. Furthermore, an ECA rule is adopted for definition consistency maintenance. Finally, extensive simulation experiments are conducted in SPDMS. The simulation results show that the 2DCMA algorithm has better performance than that of Mork＇s when maintaining data consistency. And the 2DCMA algorithm has better performance than that of centralized view maintenance algorithm when maintaining definition consistency.
基金the National Natural Science Foundation of China(Nos.61373030 and 71171132)
文摘Real-time collaborative editing(RTCE)can support a group of people collaboratively work from distributed locations at the same time.However,consistency maintenance is one key challenge when different types of conflicts happen.Therefore a common synchronous mechanism is proposed to support consistency maintenance in the process of multi-view business modeling.Based on operation analysis on different views of models in the real-time collaborative editing system,detection of potential conflicts is realized by means of a decision-making tree.Then consistency maintenance provides a comprehensive and applicable conflicts detection and resolution for collaborative business modeling.Finally,a prototype of collaborative multi-view business modeling system is introduced to verify the approach.The point is that the mechanism proposes a comprehensive solution for collaborative multi-view business modeling.
