A recovery method using recently updated record information in shared-nothing spatial database cluster

A shared-nothing spatial database cluster is system that provides continuous service even if some system failure happens in any node. So, an efficient recovery of system failure is very important. Generally, the existing method recovers the failed node by using both cluster log and local log. This method, however, cause several problems that increase communication cost and size of cluster log. This paper proposes novel recovery method using recently updated record information in shared-nothing spatial database cluster. The proposed technique utilizes update information of records and pointers of actual data. This makes a reduction of log size and communication cost. Consequently, this reduces recovery time of failed node due to less processing of update operations.     

A recovery method using recently updated record information in shared-nothing spatial database cluster

A shared-nothing spatial database cluster is system that provides continuous service even if some system failure happens in any node. So, an efficient recovery of system failure is very important. Generally, the existing method recovers the failed node by using both cluster log and local log. This method, however, cause several problems that increase communication cost and size of cluster log. This paper proposes novel recovery method using recently updated record information in shared-nothing spatial database cluster. The proposed technique utilizes update information of records and pointers of actual data. This makes a reduction of log size and communication cost.Consequently, this reduces recovery time of failed node due to less processing of update operations.     

Parallel recovery method in shared-nothing spatial database cluster system

Shared-nothing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed. However if the failed node wouldn‘t be recovered quickly, whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques, external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly. Also recovery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.     

Parallel recovery method in shared-nothing spatial database cluster system

Shared-nothing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed.However if the failed node wouldn't be recovered quickly, whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques, external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly.Also recovery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.     

Parallel recovery method in shared-nothing spatial database cluster system

Shared-notliing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed. However if the failed node wouldn’t be recovered quickly,whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques,external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly. Also reccvery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.     

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 managese parating aspatial data version and spatial data version to decrease waste of storage for record version and improve concurrency among transactions.     

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.     

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.     

一种分布式实时内存数据库的系统故障恢复模式

提出了一种适合分布式实时内存数据库的、基于日志的故障恢复模式.在该恢复模式中,日志记录被存储在非易失高速存储设备中,非易失日志存储区依据事务类型被分成四个不同的日志分区,不同类型事务的日志被存储在不同的日志分区;采用了执行频率动态可调的模糊检验点模式,在检验点执行过程中,一些无用的日志记录被删除;故障发生后,系统重启、恢复时,分区重装策略被采用;恢复算法结合相关恢复协议,确保了全局事务故障的原子性.实验显示,该故障恢复模式明显地改进了系统性能,提高了实时事务满足截止期的比率.     

An Efficient Crash Recovery Technique for Real-Time Main Memory Database

This paper presents an efficient recovery scheme suitable for real-time main memory database. In the recovery scheme, log records are stored in non-volatile RAM which is divided into four different partitions based on transaction types. Similarly, a main memory database is divided into four partitions based data types. When the using ratio of log store area exceeds the threshold value, checkpoint procedure is triggered. During executing checkpoint procedure, some useless log records are deleted. During restart recovery after a crash, partition reloading policy is adopted to assure that critical data are reloaded and restored in advance, so that the database system can be brought up before the entire database is reloaded into main memory. Therefore down time is obvionsly reduced. Simulation experiments show our recovery scheme obviously improves the system performance,and does a favor to meet the deadlines of real-time transactions.     

混合动态数据库集群的并行空间连接优化算法

传统算法数据划分冗余度和倾斜度高,无用连接数据多,降低负载均衡性,对整体效率产生不好的影响,不适于实际应用。为此,面向混合动态数据库集群提出一种新的并行空间连接优化算法。采用网格划分法对数据进行划分,依据空间数据划分结果获取数据分布状态,计算节点按照数据分布状态得到候选集。通过平面扫描形成若干子空间连接的子任务,利用构建节点花费模型,依据花费模型对并行空间连接所需的平均节点访问个数进行评估,把候选任务集分配至不同计算节点,在不同节点执行并行空间连接操作。通过边界过滤策略,删除不可能有结果的元组,提高效率,增强算法的实用性。实验结果表明,所提算法适于实际应用,效率高。     

An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client‘s queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

应用型地理信息系统空间数据库的分析和设计

提出将软件工程中结构化系统分析和设计的思想应用于应用型地理信息系统空间数据库的分析和设计中；并在此基础上探讨了空间数据库分析和设计的过程和一些关键技术，包括图块结构的划分、图层组织和属性数据的组织，以及结构化的分析和设计方法如何应用于空间数据库中属性数据库的设计，同时结合ARC／INFO地理信息系统软件和云南小湾水电站工程建设的实际情况，设计了一个施工设施管理空间数据库原型。     

城市部件信息管理系统数据库的设计

为实时和准确掌握城市部件的现状(内容、属性、数量、位置和状态等),现今社会采用数字化城市部件管理的方法,它是城市经济、社会活动的基本载体,是提高城市管理效率和信息化水平的根本保证。本文在介绍空间数据库管理模式、空间数据引擎、Geodatabase模型和数据库设计的过程中,重点叙述了城市部件信息管理系统中空间数据库和属性数据库的设计方法及过程;给出了空间数据库3种数据的建立机制及属性数据库的设计步骤。还以专题的形式,设计了一套完整的数据库快速索引机制来保证地理坐标和地址编码的快速匹配,完成了空间数据和属性数据的各级汇总、加工、校验和入库。预测城市中各部件的管理效率会得到极大地提高,同时也为后期数字化城市中各功能的实现打下了坚实的基础。     

嵌入空间数据库的地图服务

传统的Web地图服务必须由运行于独立进程的“地图服务器”提供．栅格地图不能直接通过查询谓词“select”从空间数据库中得到．通过在空问数据库增加模块提供查询谓词“select”对地图服务的支持．地图渲染模块负责地图绘制,Symbol扩充数据类型为空间数据提供不同的地图表现形式．扩充后的空问数据库被称作“MapBase”．最后提供了MapBase的应用实例,同时和以往的地图服务方式进行了比较．实验表明,扩展空间数据库的方式简化了地图服务的系统结构,便于WebGIS二次开发．图6,参9．     

城市空间信息系统动力学演化机理与应用

根据系统动力学理论和方法，构建了城市空间系统动力学过程模型，揭示了空间结构-空间认知-空间行为-空间过程-空间结构的演化过程。提出城市空间数据在时间、空间和过程上分为不同的层次，具有时态特性。构建了城市空间信息系统动力学过程模型，进而得出城市空间信息系统动力学演化机理。在此基础上．构建了空间信息基础框架数据库动态稳定模式，实现了数据库的动态稳定性。同时保证了各部门共同建设和分享一个框架数据库，避免了每隔几年就需要大规模修测城市地形数据库。新的工作流模式的应用．改变了传统粗放式的管理模式。     

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。     

An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

基于MAPGIS的韩城矿区煤层气空间数据库的建立

介绍了韩城矿区煤层气空间数据库的系统组成、设计思路及其在煤层气资源评价中的意义。该空间数据库由属性数据库和图形数据库组成。属性数据库是在Visual Foxpr06．0平台上以全矿区2^#、3^#、5^#、11^#煤层为对象建立起来的。图形数据库是在MAPGIS6．0平台上建立基本地理图形信息、基础地质图形信息、水文地质图形信息、盖层图形信息、煤层气储集层图形信息、储层基底图形信息和专题图形信息等。该空间数据库的建立，可方便查询该区与煤层气有关的地质资料，同时为煤层气合理开发利用和管理决策提供了科学依据。     

基于GIS的面向对象人口空间数据库设计

在"乌鲁木齐市城市远景规划修编项目"实施过程中,利用地理信息系统的强大数据管理和空间分析功能,有效地整合现有的规划图纸资料和街道统计数据,建立基于GIS的面向对象人口空间数据库,实现空间数据和属性数据的统一存储和管理.在此基础上进行人口规模、密度和分布变化规律的空间分析和研究,为未来乌鲁木齐市城市远景规划和发展建设提供数据支持和决策依据.