Version based spatial record management techniques for spatial database management system

The search operation of spatial data was a principal operation in existent spatial database management system, but the update operation of spatial data such as tracking are occurring frequently in the spatial database management system recently. So, necessity of concurrency improvement among transactions is increasing. In general database management system, many techniques have been studied to solve concurrency problem of transaction. Among them, multi-version algorithm does to minimize interference among transactions. However, to apply existent multi-version algorithm to improve concurrency of transaction to spatial database management system, the waste of storage happens because it must store entire version for spatial record even if only aspatial data of spatial record is changed. This paper has proposed the record management techniques to manage separating aspatial data version and spatial data version to decrease waste of storage for record version and improve concurrency among transactions.     

A solution for concurrency control and long transaction management in SDBMS

The problem of long transactions is a significant problem in spatial database. The checkout mechanism and multi-version mechanism are two kind methods of solving the problem of long transactions. In this paper, we present a Shallow Version Management mechanism to realize multi-version mechanism in spatial database. And we introduced a increment storage and dynamic version views building method to improve efficiency of storing and consulting. We also illuminate how to resolve the problem of long transaction concurrency control in spatial database by using multi-version mechanism. At the end of this paper, we introduce some required means to version management in spatial database, like converge, compress and delete.     

A solution for concurrency control and long transaction management in SDBMS

The problem of long transactions is a significant problem in spatial database.The checkout mechanism and multi-version mechanism are two kind methods of solving the problem of long transactions. In this paper, we present a Shallow Version Management mechanism to realize multi-version mechanism in spatial database. And we introduced a increment storage and dynamic version views building method to improve efficiency of storing and consulting. We also illuminate how to resolve the problem of long transaction concurrency control in spatial database by using multi-version mechanism. At the end of this paper, we introduce some required means to version management in spatial database,like converge, compress and delete.     

可变时标并发控制

提出了一种新的利用时标进行数据库并发控制的方法,与以前的时标法不同的是,事务的时标在其执行过程中是可变的,一个事务仅当要产生不一致性时才被撤消.该方法比以前的时标法有更大的并发性.     

实时数据库系统的面向对象数据模型及调度策略研究

分析了实时数据库系统中的数据和事务的特性。提出了一种实时面向对象的数据模型,它充分考虑了实时数据库系统对数据和事务的逻辑及时间一致性的要求。依据这种数据模型,可以设计出各种合适的并发控制协议及事务调度策略,以提高实时数据库系统的性能。     

分布式数据库中的一种多考贝管理算法

在分布数据库中,一个数据项可在多个结点上放有考贝,这是增加系统可靠性与效率的有效手段。但系统必须维护考贝之间的相互一致性。在通常情况下,相互一致性是可以保持的。但在结点失效时,如不特殊处理,事务就有可能破坏相互一致性,发生不一致的引用从而产生错误的结果。为此,我们以基本2PL作为分布式数据的并发控制机制,设计了一个结点失败时的多考贝管理算法,它可使系统在结点失败时正常运行,产生出正确的结果。     

一种实时数据库系统的多版本两段锁的并发控制协议

详细讨论了与并发控制有关的实时数据和实时事务的各种特征以及分类,主要包括：实时数据对象可分为映像对象、导出对象和不变对象;实时事务按功能分类可分为数据接收事务、数据处理事务和控制事务;数据接收事务和控制事务是硬实时事务,是不能等待和阻塞的．然后,根据这些特点对传统数据库系统的多版本并发控制机制进行了扩展,提出了实时数据库系统的多版本两段锁及多版本带夭折两段锁协议,且证明了两者都是冲突可串行化的．前者对于只读事务是没有延迟的,对于硬实时事务的延迟也很小;后者对硬实时事务不产生任何延迟,这两个协议都能较好地保证实时事务和实时数据的定时限制．     

基于优先级的多版本两阶段锁并发控制协议

提出了适用于移动实时数据库环境下基于优先级的多版本两阶段锁并发控制协议,它结合多版本并发控制机制和两阶段锁机制的优点,引入优先级概念对事务进行优先级别的划分,分情况进行考虑.通过仿真实验模拟,对该协议进行了性能测试,并与其他协议进行了比较,实验结果表明:该协议的性能表现良好.     

基于概念事务模型的分布式并发控制方法

在提出描述事务系统的“概念事务模型”的概念和建造方法后,给出一种基于概念事务模型的分布式并发控制方法．这种方法仅对能够导致冲突的事务施以全局同步,既简化了分布式并发控制机制,又提高了系统的并行度     

基于商业连锁经营的会员管理系统

为在商业连锁经营中,实现会员信息共享,基于Windows平台,采用分布式数据库与PB(Power Builder)相结合的方法,研制开发了连锁经营中会员管理系统,给出了其设计和实现方法.与单店系统相比,该系统通过虚拟专网VPN(Virtual Private Network)实现连锁店和总部之间的通信,连锁店和总部均采用ORACLE 8i数据库,构成同构同质型分布式数据库系统;在数据的分片与分配上,对各连锁店单独使用的数据采用水平分片非冗余分配的方法,节约空间 20%;会员信息和会员消费明细账没有分片,冗余分配在各店的站点上形成多个副本,提高了系统的可靠性,保证会员消费时只与本地数据库通信;会员数据通过数据管道实现上传和下载,使用并发控制和恢复机制维持分布式事务性质,并保证数据的一致性和完整性.该系统已成功应用于某商厦会员管理工作中,并取得了很好的效果,会员人数增加60%,达10余万人,并逐渐成为企业长期忠实的顾客,会员消费占总消费的三分之二以上,成为企业利润的源泉.     

A solution for digital image management in spatial databases

Digital Orthographic Map (DOM) can be used in various applications because it contains both image features and terrain information. Spatial database management systems aim at the effective and efficient management of data related to a space,engineering design and so on. Thereby spatial database provides an efficient solution for managing DOM. According to large amounts of the DOM data in storage, a data compression based on wavelet is introduced into the storage. Another strategy to solve this problem is to decompose the raw image into tiles and store the tiles individually as separate tuples. The metadata of DOM can be used to organize and manage spatial information,especially for spatial data sharing and fast locating. A tool for browsing, zooming and querying the DOM data is also designed. We implemented these ideas in SISP (Spatial Information Sharing System) and applied the subsystem into the DOM management of Beijing City, which is an component of the Beijing Spatial Information Infrastructure.     

A solution for digital image management in spatial databases

Digital Orthographic Map (DOM) can be used in various applications because it contains both image features and terrain information. Spatial database management systems aim at the effective and efficient management of data related to a space, engineering design and so on. Thereby spatial database provides an efficient solution for managing DOM. According to large amounts of the DOM data in storage, a data compression based on wavelet is introduced into the storage. Another stratcgy to solve this problem is to decompose the raw image into tiles and store the tiles individually as separate tuples. The metadata of DOM can be used to organize and manage spatial information, especially for spatial data sharing and fast locating. A tool for browsing, zooming and querying the DOM data is also designed. We implemented these ideas in SISP (Spatial Information Sharing System) and applied the subsystem into the DOM management of Beiiing City, which is an component of the Beijing Spatial Information Infrastructure.     

An efficient spatio-temporal data structure for multi version management of engineering drawings

In the engineering database system, multiple versions of a design including engineering drawings should be managed efficiently. The paper proposes an efficient spatial data structure, that is an expansion of the R-tree and HR-tree, for version management of engineering drawings. A novel mechanism to manage the difference between drawings is introduced to the HR-tree to eliminate redundant duplications and to reduce the amount of storage required for the data structure. Data management mechanism and structural properties of our data structure called the MVR -tree are described.     

数字农业空间信息管理平台的设计与实现

根据数字农业空间信息管理平台的建设目标和要求,进行了空间数据库和属性数据库的设计与建设.在此基础上,采用SQL Server2000、ArcSDE、VB6.0和ArcEngine四者结合进行了平台总体架构和功能的设计,并进行了平台的开发,实现了平台与数据管理、地图基本操作、农业信息综合查询、农业空间分析、土地斑块调整、制图与输出系统等功能.     

实时主动数据库并发控制协议

提出了实时主动数据库系统实时多版本两阶段封锁并发控制协议(RTMV2PL). 该协议将多版本并发控制的优点和两阶段封锁并发控制机制优点结合起来. 多版本两阶段封锁机制消除了只读事务和更新事务的冲突, 只读事物从不重启动. 对实时主动数据库系统的事务优先级重新定义. 通过模拟仿真与传统的HP2PL和OCC-TI-WAIT-50协议进行比较. 研究结果表明, 并发控制协议不但能有效地降低事务的重启动率和延误截止时间率, 而且提高只读事物的响应时间. 当事务触发率高, 导致系统负载高时, 它的性能仍比其他协议的性能好.     

Research on spatial association rules mining in two direction

In data mining from transaction DB, the relationships between the attributes have been focused, but the relationships between the tuples have not been taken into account. In spatial database, there are relationships between the attributes and the tuples, and most of the associations occur between the tuples, such as adjacent, intersection, overlap and other topological relationships. So the tasks of spatial data association rules mining include mining the relationships between attributes of spatial objects, which are called as vertical direction DM, and the relationships between the tuples, which are called as horizontal direction DM. This paper analyzes the storage models of spatial data, uses for reference the technologies of data mining in transaction DB, defines the spatial data association rule, including vertical direction association rule, horizontal direction association rule and twodirection association rule, discusses the measurement of spatial association rule interestingness, and puts forward the work flows of spatial association rule data mining. During twodirection spatial association rules mining, an algorithm is proposed to get nonspatial itemsets. By virtue of spatial analysis, the spatial relations were transferred into nonspatial associations and the nonspatial itemsets were gotten. Based on the nonspatial itemsets, the Apriori algorithm or other algorithms could be used to get the frequent itemsets and then the spatial association rules come into being. Using spatial DB, the spatial association rules were gotten to validate the algorithm, and the test results show that this algorithm is efficient and can mine the interesting spatial rules.     

Research on spatial association rules mining in two-direction

In data mining from transaction DB, the relationships between the attributes have been focused, but the relationships between the tuples have not been taken into account. In spatial database, there are relationships between the attributes and the tuples, and most of the associations occur between the tuples, such as adjacent, intersection, overlap and other topological relationships. So the tasks of spatial data association rules mining include mining the relationships between attributes of spatial objects, which are called as vertical direction DM, and the relationships between the tuples, which are called as horizontal direction DM. This paper analyzes the storage models of spatial data, uses for reference the technologies of data mining in transaction DB, defines the spatial data association rule, including vertical direction association rule, horizontal direction association rule and two-direction association rule, discusses the measurement of spatial association rule interestingness, and puts forward the work flows of spatial association rule data mining. During two-direction spatial association rules mining, an algorithm is proposed to get non-spatial itemsets. By virtue of spatial analysis, the spatial relations were transferred into non-spatial associations and the non-spatial itemsets were gotten. Based on the non-spatial itemsets, the Apriori algorithm or other algorithms could be used to get the frequent itemsets and then the spatial association rules come into being. Using spatial DB, the spatial association rules were gotten to validate the algorithm, and the test results show that this algorithm is efficient and can mine the interesting spatial rules.     

An efficient spatio-temporal data structure for multi version management of engineering drawings

In the engineering database system, multiple versions of a design including engineering drawings should be managed efficiently. The paper proposes an efficient spatial data structure, that is an expansion of the R-tree and HR-tree, for version management of engineering drawings. A novel mechanism to manage the difference between drawings is introduced to the HR-tree to eliminate redundant duplications and to reduce the amount of storage required for the data structure. Data management mechanism and structural properties of our data structure called the MVR -tree are described.     

油气藏开发管理GIS中空间数据库的设计及应用

油气田开发管理中具有大量的多系统、多层次的图形信息和属性信息，如何将这些地理数据组织成完整的空间数据库是GIS建立过程中相当重要的一项基础工作．针对油气藏开发管理中涉及的数据复杂多样的特殊性，介绍了如何建立油气藏开发管理空间数据库．并对在油气藏开发管理地理信息系统中，如何充分应用空间数据库来辅助油气藏开发管理做了简单说明。     

信息系统事务一致性研究与实现

在应用层次上,数据库一致性是通过事务一致性体现的,在介绍事务间一致性和事务内一致性概念的基础上,讨论了基于封锁机制的并发控制和基于日志的提交控制技术,分析了事务操作的补偿性问题,以DB2/400数据库为例,探讨了实现事务完整性和数据库一致性的方法,给出了应用程序实例,大量的实际应用表明该方法是可靠有效的.