基于SNMP协议的公共机房管理软件设计

针对公共机房管理上的要求 ,采用软件技术实现了计费管理、权限管理、实时监控等功能。应用软件采用三层结构的形式实现数据库操作 ,利用SNMP协议作为客户端与数据库访问模块的主要通信协议 ,简化了客户端软件设计 ,提高了软件的可靠

Highly-efficient SPT arithmetic of fast freecube calculation

分析了目前国内外数据立方体计算的研究现状,首先在free-set的概念上,挖掘free-set的性质,建立了FreeCube的概念结构。然后基于BUC算法,充分考虑到free-set的性质,在对维划分的选择和free-set判断上去掉了不必要的划分和判断,从而提出了一种计算FreeCube的高效算法SPT,最后从多个角度进行了实验,并与相关工作做了对比,证明该算法具有一定的优越性。The current domestic and international research situation of data cube calculation are analyzed.Its merits and demerits are pointed out.The free-set property is excavated and the concept construction of freecube on the free-set conception is established.With regard to freecube calculation,fully considering the free-set characteristics while combining the characteristics of BUC's cal-culation,an efficient calculation way SPT is put forward.After the related work is compared,the result show the superiority of the algorithm.浙江理工大学科学基金项目(111251A4Y04002

A Join and Aggregate Algorithm for Complex Multi-Dimensional Hierarchies

由于数据仓库中存储着不同粒度、容量巨大的数据记录 ,所以如何有效地执行联机分析处理 (OLAP)查询操作 ,特别是连接和聚集操作 ,便成为数据仓库领域的核心问题之一 为此 ,提出了一种降低连接和聚集操作的新算法 (joinandaggregationbasedonthecomplexmulti dimensionalhierarchies,JACMDH) 算法充分考虑了复杂多维层次的特点 ,在原有的位图连接索引 (bitmapjoinindex)的基础上 ,采用层次联合代理 (hierarchycombinedsurrogate)和预先分组排序的方法 ,使得复杂的多维层次上的连接和聚集操作转化成事实表上的区域查询 ,从而在处理多维层次聚集的同时 ,提高了连接和聚集的效率 算法性能分析和实验数据表明 ,JACMDH算法和目前流行的算法相比 ,其性能有显著的提高Enormous volume of data reside in data warehouse, so it is important to process efficiently expensive queries including join and aggregate operation. In this paper, a new method (JACMDH algorithm) is proposed for processing time-consuming join and aggregate operation. This algorithm takes into consideration the characteristics of the complex multi-dimensional hierarchies and adopts hierarchy combined surrogate/pre-grouping and pre-sorting on the basis of bitmap join index. It improves the join and aggregate efficiency by translating join and aggregate operation of complex multi-dimensional hierarchies into range queries of fact table. The performance analysis and the experimental result, show that the performance of JACMDH algorithm can be improved dramatically, compared with current method for aggregation query evaluation.福建省自然基金项目 (A0 3 10 0 0 8) ;; 福建省高新技术研究开放计划重点基金项目 ( 2 0 0 3H0 43

Dynamic Selection of Materialized Views of Multi Dimensional Data with a Multi-Users and Multi Windows Method

多维视图动态维护是数据仓库领域当前研究的一个热点 随着数据仓库的普及 ,将有越来越多的各种类型的用户使用OLAP工具满足各自特定的分析需求 现有的各种视图选择方法没有考虑不同类型用户的特点 ,从而存在一些缺陷 提出多用户多窗口方法 ,充分考虑用户的差异 ,利用单个用户在查询时的相对有规律性 ,为用户划分级别 ,并为每个用户设置相应级别的用户视图窗口 ,从而合理地利用了系统有限的资源 ,提高了查询响应速度 ,也保证了特殊用户对查询性能的特殊需求 ;给出了相关的定义和MUMW算法 ,并阐述了多用户多窗口方法的优点Dynamic selection of materialized views of multi dimensional data is one of the most researched aspects in the field of data warehouse; With the increasing use of data warehouse, there will be accordingly more and more different kinds of users making use of OLAP tools to complete their analytical work; The existing methods being used to select views do not take into account the characteristic of various kinds of users, and therefore have some defects; A multi users and multi windows method is presented here, which considers the disparity among various users and makes use of the rule of the users' queries In the method, all users are divided into three groups with different grade and each user is accordingly endowed with user view window of certain grade Such method leads to the reasonable use of the limited space resource and also speeds up the response of query, which stipulates satisfying some special needs of certain user; Some related conceptions and MUMW algorithm are also put forward here, and at the same time, the advantages of this method are described福建省自然科学基金项目 (A0 3 10 0 0 8);; 福建省高新技术研究开放计划重点项目 ( 2 0 0 3H0 43

Dynamic Selection of Materialized Views of Multi-Dimensional Data with a Multi-Users and Multi-Windows Method

多维视图动态维护是数据仓库领域当前研究的一个热点 随着数据仓库的普及 ,将有越来越多的各种类型的用户使用OLAP工具满足各自特定的分析需求 现有的各种视图选择方法没有考虑不同类型用户的特点 ,从而存在一些缺陷 提出多用户多窗口方法 ,充分考虑用户的差异 ,利用单个用户在查询时的相对有规律性 ,为用户划分级别 ,并为每个用户设置相应级别的用户视图窗口 ,从而合理地利用了系统有限的资源 ,提高了查询响应速度 ,也保证了特殊用户对查询性能的特殊需求 ;给出了相关的定义和MUMW算法 ,并阐述了多用户多窗口方法的优点。Dynamic selection of materialized views of multi-dimensional data is one of the most researched aspects in the field of data warehouse; With the increasing use of data warehouse, there will be accordingly more and more different kinds of users making use of OLAP tools to complete their analytical work; The existing met hods being used to select views do not take into ccount the characteristic of various kinds of users, and therefore have some defects; A multi-users and multi-windows method is presented here, which considerst he disparity among various users and makes use of the rule of the users’queries1 In the method,all users are divided into three group swith different grade and each user is accordingly endowed with user view window of certain grade. Such met hod leads to the reasonable use of the limited space resource and also speeds up the response of query, which stipulates satisfying some special needs of certain user; Some related conceptions and MUMW algorithm are also put forward here, and at the same time , the advantages of this method are described.福建省自然科学基金项目(A0310008);福建省高新技术研究开放计划重点项目(2003H043

Research and Implementation of the Reading and Writing Method of Internet Files Based on J2EE and Database

文件的上传与下载是Web服务的一个重要功能。该文分析了基于HTTP协议的文件上传方式所规定的数据包结构,介绍了在Web服务器和浏览器之间传输文件的基本原理。在此基础上,利用JavaServlet及Java扩展类实现了Internet上文件的上传和下载,利用JDBC和SQLServer的image存储特性实现了各种类型文件的存储,有效地解决了文件数据的管理问题。Upload and download of files is a main function of Web services.This article analyzes the data structure when files are uploaded via HTTP,and introduces the basic principle of file transferring between Web server and browser.Method of file uploads and downloads via Java servlet and Java extension class on the Internet is given,and files are written and read from database by using JDBC and SQLServer's image property,as an example,so the man-agement problem of file data is resolved

Distributed Heterogeneous DataBase Application Based on CORBA/Java

由于企业自身发展的需要,信息支撑系统向分布式异构数据库应用系统跨越已经成为一种必然趋势。CORBA犤1犦、Java是解决该类应用的主要技术,文章讨论了这两种技术结合使用的原理,并在此基础上利用InpriseApplicationServer及相关软件,在Intranet/Internet环境下构建一个跨平台、可扩展的、可移植的、可管理的分布式异构数据库应用系统的解决方案。To meet the demand of enterprise 's development ,It is the trend that the information support system span distributed heterogeneous database application.In this paper,the solution to construct a distributed heterogeneous database application which can be extended and transplanted over different platform,is introduced,including the techniques of CORBA/Java and inprise application server

Research on Web-Based Integrated Environment for Data Warehouse

随着Web技术的日臻成熟,基于Web的数据仓库技术显示了强大的优势,更好地适应了企业生存发展的需要。本文描述了一个基于Web的数据仓库集成环境(WIEDW)及其主要技术,将数据仓库的设计、部署、管理与利用集成在同一个平台中,使得数据仓库具有良好的整体性能,为用户提供一个数据仓库的设计、运行、维护平台环境,提高了企业建立、维护数据仓库应用系统对决策活动的实用性。该集成环境架构在J2EE软件体系结构上,利用了Jdbc、JavaBean等技术,使系统具有良好的可靠性、可扩展性及安全性。With the rapid growth of Web technologies,the Web-based data warehouse has become a dominant trend,because it can be more beneficial to enterprises. This paper describes a Web-based Integrated Environment for Data Warehouse (WIEDW) and the main technologies which integrate the design,running and maintenance data warehouse, and it will improve enterprises to build and maintain data warehousing for decision. The integrated Environment is based on the J2EE software architecture, which uses the techniques of Jdbc and JavaBean,and the reliability, expansibility and security of the system are favorable.福建省自然基金(A0310008);; 福建省高新技术研究开放计划重点项目资助(2003H041

Maximal Frequent Subtree Mining Algorithm Based on Subtree Constraint

目前大多数频繁子树算法都是挖掘频繁子树完全集,这些算法数据搜索空间的内存开销和输出的结果集都非常庞大。为了减小结果集,提出基于子树约束的最大频繁子树算法——CSMTrEEMInEr,采用垂直和层次扩展的方法来枚举频繁子树,并使用覆盖关系来对不可能生成最大频繁子树的模式进行删除。实验结果验证CSMTrEEMInEr算法的有效性和稳定性。Most algorithms for mining frequent subtrees are mining completed frequent sets, so the searching space and results are very huge.For reducing the results' number, proposes CSMTreeMiner, a maximal frequent subtree mining algorithm based on subtree constraint.This algorithm uses vertical and level extension technique to enumerate subtrees, and uses the cover relationship to delete the pattern which is impossilbe to generate maximal frequent subtree.Experimental result shows that CSMTreeMiner is effective and stable.国家自然科学基金(No.50604012

An Incrementing Update Algorithm for Star Schema

在进行数据仓库的OLAP联机分析处理时,通常采用预先聚集(Aggregate)操作生成概括数据的方法提高查询效率;但是,基于星型模型的数据仓库中的维表的纠错改变和自然改变将会引发概括数据的不正确问题.本文通过研究星型模型维表及其变化的特点,提出了一种增量更新算法,在几乎不增加空间的情况下,降低时间复杂度的增量更新;并通过性能验证,分析算法的可行性.In dealing with on-line analytical processing, in order to improve the querying efficiency, people often pre-aggregate the data in the data warehouse. But the corrective and natural changing of dimensional tables based on star schema make the aggregate data false. In this article, I advance an incrementing update algorithm by studying dimensional tables of star schema and their changing characteristic. This algorithm reduce the time cost and increase the space cost hardly. Finally,this article analyze the algorithm's performance by validating its feasibility