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中国资讯行数据库的检索
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作者 陆宏弟 《情报理论与实践》 CSSCI 北大核心 2002年第3期223-226,共4页
The coverage of 12 online databases of China INFOBANK is introduced,and the information retrieval strategies for these databases are detailed with some examples by the author.
关键词 中国资讯行数据库 检索方法 简易检索 专业检索 二次检索
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国内外大型商情数据库检索 被引量:3
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作者 闫海新 《图书馆工作与研究》 CSSCI 北大核心 2001年第5期47-49,共3页
本文简要介绍了国内外几个大型商情数据库的特点及使用方法 ,旨在促进国内公司、企业及科研机构快速。
关键词 商情数据库 商情信息数据库 中国资讯行数据库 商业资源数据库 外国
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关于DB_2数据库的备份与恢复方法
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作者 孙建坤 《金融科技时代》 1999年第2期47-48,共2页
数据库管理系统的一个重要任务,就是在硬件或软件出现问题或突然掉电以及其它异常情况出现时,防止数据的丢失,进行数据库的恢复。DB<sub>2</sub>为数据库管理员提供了很多功能来保护数据库,并可以把它们从失败中恢复。
关键词 数据库管理员 日志文件 恢复方法 数据库管理系统 备份恢复 行数据库 应用数据库 开发应用 数据库备份 保护数据
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浅谈大数据处理中的数据库I/O问题
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作者 陈心咏 《信息通信》 2018年第6期133-134,共2页
基于文件的数据库系统处理海量数据时,常常会遭遇到性能瓶颈。例如:返回数据等待时间长、操作数据库卡顿、无法操作数据、超时、出现其他意外错误等等,这些一般最常见的是磁盘操作产生的I/O问题导致的。文章主要针对I/O问题的进行探讨,... 基于文件的数据库系统处理海量数据时,常常会遭遇到性能瓶颈。例如:返回数据等待时间长、操作数据库卡顿、无法操作数据、超时、出现其他意外错误等等,这些一般最常见的是磁盘操作产生的I/O问题导致的。文章主要针对I/O问题的进行探讨,并提出优化改进方案。 展开更多
关键词 I/O速度 I/O效率 计划 数据库 列式数据库
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油气田工业大数据建设与研究 被引量:1
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作者 孟亮 王伟 +2 位作者 王俊丽 肉鲜古力 孙业 《信息系统工程》 2020年第10期108-110,共3页
自21世纪初以来,诸如移动物联网,云计算和物联网等新一代信息技术发展迅速。"中国制造2025"成功推出,极大加速了当代中国传统工业制造企业向"智能"互联网时代的工业企业转变。典型的技术革命为石油和天然气行业的... 自21世纪初以来,诸如移动物联网,云计算和物联网等新一代信息技术发展迅速。"中国制造2025"成功推出,极大加速了当代中国传统工业制造企业向"智能"互联网时代的工业企业转变。典型的技术革命为石油和天然气行业的新转型和升级奠定了基础。论文结合新疆油田公司采气一厂实际情况,引入天行实时数据库,借助信息化与物联网等相关技术,构建厂级工业大数据平台,为气田生产管理、生产优化提供统一标准的数据服务,最后,建立具有综合意识,自动控制,趋势预测,优化决策,辅助存储和增产,环保与安全,高效运行和精细控制的智能气田,满足气田未来高效开发管理的需要。 展开更多
关键词 实时数据库 工业大数据 集群部署 实时数据深化应用
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银行信贷登记咨询系统运行中存在的问题及建议
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作者 樊秀平 周敬东 《河北金融》 2003年第11期45-45,共1页
一、存在问题 (一)支持信贷咨询系统运行软件环境问题。从目前情况看,各家金融机构使用的运行软件不一致。如中行、农发行、城乡信用社使用的是人民银行开发的系统软件,而工行、农行、建行则分别使用自己开发的系统软件,由于存在接口的... 一、存在问题 (一)支持信贷咨询系统运行软件环境问题。从目前情况看,各家金融机构使用的运行软件不一致。如中行、农发行、城乡信用社使用的是人民银行开发的系统软件,而工行、农行、建行则分别使用自己开发的系统软件,由于存在接口的衔接和程序运行差异性问题,导致接口行向人行数据库输入有关信息时。 展开更多
关键词 信贷登记咨询系统 金融机构 系统软件 人民银 信贷业务 环境问题 存在问题 差异 城乡信用社 行数据库
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Design and Implementation of a Heterogeneous Database System over the Intranet
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作者 姚领众 邢艳辉 +3 位作者 宋瀚涛 杨楠 郭贵锁 孙丹 《Journal of Beijing Institute of Technology》 EI CAS 1998年第1期92-99,共8页
Aim To develop a heterogeneous database united system(HDBUS)that combines the local database of Oracle, Sybase and SQL server distributed on different server into a global database,and supports the global transaction... Aim To develop a heterogeneous database united system(HDBUS)that combines the local database of Oracle, Sybase and SQL server distributed on different server into a global database,and supports the global transaction management and parallel query over the Intranet Methods In the designing and implementation of HDBUS two important concepts heterogeneous tables join. Results and Conclu- tion The first concept can be used to process the parallel query of multiple database server, the second one is the key technology of heterogeneous is the key technology of heterogeneous distribute database. 展开更多
关键词 INTRANET heterogeneous database parallel bridge heterogeneous tables join
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运用计算机管理馆藏全宗的尝试
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作者 王勇 《北京档案》 北大核心 1997年第12期21-21,共1页
运用计算机管理馆藏全宗的尝试王勇1992年,国家发布全宗单标准,就全宗单的内容构成和适用范围作了规定。这不仅规范了全宗单的内容、格式与填写方法,也对档案馆全宗统计与管理提供了标准,规范了全宗管理工作。1996年西城区... 运用计算机管理馆藏全宗的尝试王勇1992年,国家发布全宗单标准,就全宗单的内容构成和适用范围作了规定。这不仅规范了全宗单的内容、格式与填写方法,也对档案馆全宗统计与管理提供了标准,规范了全宗管理工作。1996年西城区档案馆结合对馆藏全宗的清点核对,贯... 展开更多
关键词 计算机管理 全宗 管理数据库 检索工具 行数据库 保管期限 档案馆 对比分析 单标准 档案管理人员
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DSS Scheme for Operation Optimization Problem on Power Plants 被引量:1
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作者 江浩 徐治皋 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期212-215,共4页
Based on the target analysis of the operation optimization for power plants, a novel system scheme called operation optimization decision support system (OODSS) is brought forward. According to the structure and desig... Based on the target analysis of the operation optimization for power plants, a novel system scheme called operation optimization decision support system (OODSS) is brought forward. According to the structure and design thinking of decision support system (DSS), the overall structure of the OODSS is studied, and the scheme of the sub systems in the OODSS such as the user interface system, the problem processing system, the database system, the model base system, the expert system (ES) and the data mining sy... 展开更多
关键词 power plant operation optimization DSS database system model base system data mining expert system
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RLG、WLN和LC三个系统将连成一个网络
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作者 晓通 《现代图书情报技术》 1983年第2期31-31,共1页
关键词 三个系统 N和 性网络 研究图书馆 行数据库 查询与检索 资源委员会 计算机系统 共享目录 规范系统
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科学,技术和医学
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作者 杨则正 《管理观察》 1998年第10期59-59,共1页
关键词 行数据库 描述数据库 内容和结构 推广者 ONLINE 题目的 医学 手册
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迈至科公司
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《中国经济和信息化》 1997年第26期69-69,共1页
公司名称:北京迈至科网络技术处理有限责任公司 主页地址:www.magicw3.com 更新频率:每日 维护人员数量:8人 开通时间:1996年3月 WWW服务器的硬、软件配置:双pentiuum pro CPU服务器 Windows NT 4.0 IIS 3.0 信息来源及权威性:由本公司... 公司名称:北京迈至科网络技术处理有限责任公司 主页地址:www.magicw3.com 更新频率:每日 维护人员数量:8人 开通时间:1996年3月 WWW服务器的硬、软件配置:双pentiuum pro CPU服务器 Windows NT 4.0 IIS 3.0 信息来源及权威性:由本公司自己提供 注:由于涉及公司机密,站点访问率暂不公布。 展开更多
关键词 域名 会议系统 网友 INTERNE 访问者 访问统计 行数据库 公司站点 搜索引擎 数据插入
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FOXBASE+的安全设置
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作者 徐文荣 《中国金融电脑》 1995年第5期54-55,共2页
FOXBASE+的安全设置人民银行山东德州地区支行电脑部徐文荣任何一个数据库应用系统都应层层设置安全性保护措施。首先是硬盘的物理加锁;其次是操作系统级和网络级的维护,NOVELL网络软件的文件授权(GRANT与撤权(... FOXBASE+的安全设置人民银行山东德州地区支行电脑部徐文荣任何一个数据库应用系统都应层层设置安全性保护措施。首先是硬盘的物理加锁;其次是操作系统级和网络级的维护,NOVELL网络软件的文件授权(GRANT与撤权(REVOKE);再是数据库管理系统... 展开更多
关键词 FOXBASE+ 数据库应用系统 行数据库 输入子程序 安全设置 口令 山东德州 操作员 人民银 系统级
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Nested Transaction Concurrency Control in Parallel Real-Time Dat-abases 被引量:7
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作者 潘怡 卢炎生 《Journal of Donghua University(English Edition)》 EI CAS 2005年第2期114-119,共6页
An integrated method for concurrency control in parallel real-time databases has been proposed in this paper. The nested transaction model has been investigated to offer more atomic execution units and finer grained c... An integrated method for concurrency control in parallel real-time databases has been proposed in this paper. The nested transaction model has been investigated to offer more atomic execution units and finer grained control within in a transaction. Based on the classical nested locking protocol and the speculative concurrency control approach, a two-shadow adaptive concurrency control protocol, which combines the Sacrifice based Optimistic Concurrency Control (OPT-Sacrifice) and High Priority two-phase locking (HP2PL) algorithms together to support both optimistic and pessimistic shadow of each sub-transaction, has been proposed to increase the likelihood of successful timely commitment and to avoid unnecessary replication overload. 展开更多
关键词 Parallel Database Peal-Time Database Nested Transaction Concurrency Control
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An Improved Hilbert Curve for Parallel Spatial Data Partitioning 被引量:7
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作者 MENG Lingkui HUANG Changqing ZHAO Chunyu LIN Zhiyong 《Geo-Spatial Information Science》 2007年第4期282-286,共5页
A novel Hilbert-curve is introduced for parallel spatial data partitioning, with consideration of the huge-amount property of spatial information and the variable-length characteristic of vector data items. Based on t... A novel Hilbert-curve is introduced for parallel spatial data partitioning, with consideration of the huge-amount property of spatial information and the variable-length characteristic of vector data items. Based on the improved Hilbert curve, the algorithm can be designed to achieve almost-uniform spatial data partitioning among multiple disks in parallel spatial databases. Thus, the phenomenon of data imbalance can be significantly avoided and search and query efficiency can be enhanced. 展开更多
关键词 parallel spatial database spatial data partitioning data imbalance Hilbert curve
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Improved Pattern Tree for Incremental Frequent-Pattern Mining 被引量:1
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作者 周明 王太勇 《Transactions of Tianjin University》 EI CAS 2010年第2期129-134,共6页
By analyzing the existing prefix-tree data structure, an improved pattern tree was introduced for processing new transactions. It firstly stored transactions in a lexicographic order tree and then restructured the tre... By analyzing the existing prefix-tree data structure, an improved pattern tree was introduced for processing new transactions. It firstly stored transactions in a lexicographic order tree and then restructured the tree by sorting each path in a frequency-descending order. While updating the improved pattern tree, there was no need to rescan the entire new database or reconstruct a new tree for incremental updating. A test was performed on synthetic dataset T1014D100K with 100 000 transactions and 870 items. Experimental results show that the smaller the minimum sup- port threshold, the faster the improved pattern tree achieves over CanTree for all datasets. As the minimum support threshold increased from 2% to 3.5%, the runtime decreased from 452.71 s to 186.26 s. Meanwhile, the runtime re- quired by CanTree decreased from 1 367.03 s to 432.19 s. When the database was updated, the execution time of im- proved pattern tree consisted of construction of original improved pattern trees and reconstruction of initial tree. The experiment results showed that the runtime was saved by about 15% compared with that of CanTree. As the number of transactions increased, the runtime of improved pattern tree was about 25% shorter than that of FP-tree. The improved pattern tree also required less memory than CanTree. 展开更多
关键词 data mining association rules improved pattern tree incremental mining
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A method for improving graph queries processing using positional inverted index (P.I.I) idea in search engines and parallelization techniques 被引量:2
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作者 Hamed Dinari Hassan Naderi 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第1期150-159,共10页
The idea of positional inverted index is exploited for indexing of graph database. The main idea is the use of hashing tables in order to prune a considerable portion of graph database that cannot contain the answer s... The idea of positional inverted index is exploited for indexing of graph database. The main idea is the use of hashing tables in order to prune a considerable portion of graph database that cannot contain the answer set. These tables are implemented using column-based techniques and are used to store graphs of database, frequent sub-graphs and the neighborhood of nodes. In order to exact checking of remaining graphs, the vertex invariant is used for isomorphism test which can be parallel implemented. The results of evaluation indicate that proposed method outperforms existing methods. 展开更多
关键词 graph query processing frequent subgraph graph mining data mining positional inverted index
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Research of University Educational Administration System Bottlenecks and Overall Optimization Scheme 被引量:1
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作者 Lv Shenmin 《International Journal of Technology Management》 2014年第5期74-76,共3页
This paper analyzes of the bottleneck to influence the running efficiency of educational administration system in universities and colleges,and from the system deployment architecture, server configuration, database S... This paper analyzes of the bottleneck to influence the running efficiency of educational administration system in universities and colleges,and from the system deployment architecture, server configuration, database SQL statement optimization and other aspects, it puts forwards the optimization scheme. 展开更多
关键词 UNIVERSITY Educational administration system The bottleneck of the system The optimization scheme
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Comparative epidemiology of gastric cancer between Japan and China 被引量:64
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作者 Yingsong Lin Junko Ueda +4 位作者 Shogo Kikuchi Yukari Totsuka Wen-Qiang wei You-Lin Qiao Manami Inoue 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第39期4421-4428,共8页
AIM:To clarify the similarities and differences in gastric cancer epidemiology between Japan and China.METHODS:A comprehensive literature search of the PubMed database was performed.The relevant literature published i... AIM:To clarify the similarities and differences in gastric cancer epidemiology between Japan and China.METHODS:A comprehensive literature search of the PubMed database was performed.The relevant literature published in China was also been cited.Data on incidence and mortality rates in 2008 were obtained from the Cancer Mondial database,published by International Agency for Research on Cancer at http://www-dep.iarc.fr/.RESULTS:Gastric cancer remains a significant publichealth burden in both Japan and China.The prevalence of Helicobacter pylori(H.pylori)colonization is high in the adult populations of both countries.Accumulating evidence from intervention studies in both countries has shown the effectiveness of H.pylori eradication in reduc-ing gastric cancer incidence.There are differences,however,in many aspects of gastric cancer,including patterns of incidence and mortality,trends in the prevalence of H.pylori infection,H.pylori strains,the magnitude of risk of gastric cancer related to H.pylori infection,and associations with dietary habits.Compared with China,Japan has seen a more rapid decline in H.pylori infection among adolescents.While Japanese cohort studies have dominated the literature concerning the associations between gastric cancer and dietary habits,numerous case-control studies in China suggest a positive association between a high intake of preserved fish and vegetables and gastric cancer risk.There is a need for a multidisciplinary research approach to understand the interactions between various strains of H.pylori,host factors,and other lifestyle and environmental factors in gastric carcinogenesis in both countries.CONCLUSION:The shared high incidence of gastric cancer and high prevalence of H.pylori,as well as differences in many aspects of gastric cancer,provide an excellent opportunity to establish Sino-Japanese collaborations. 展开更多
关键词 Gastric cancer Risk factor Helicobacter pylori EPIDEMIOLOGY
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Scheduling transactions in mobile distributed real-time database systems 被引量:1
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作者 雷向东 赵跃龙 +1 位作者 陈松乔 袁晓莉 《Journal of Central South University of Technology》 EI 2008年第4期545-551,共7页
A DMVOCC-MVDA (distributed multiversion optimistic concurrency control with multiversion dynamic adjustment) protocol was presented to process mobile distributed real-time transaction in mobile broadcast environment... A DMVOCC-MVDA (distributed multiversion optimistic concurrency control with multiversion dynamic adjustment) protocol was presented to process mobile distributed real-time transaction in mobile broadcast environments. At the mobile hosts, all transactions perform local pre-validation. The local pre-validation process is carried out against the committed transactions at the server in the last broadcast cycle. Transactions that survive in local pre-validation must be submitted to the server for local final validation. The new protocol eliminates conflicts between mobile read-only and mobile update transactions, and resolves data conflicts flexibly by using multiversion dynamic adjustment of serialization order to avoid unnecessary restarts of transactions. Mobile read-only transactions can be committed with no-blocking, and respond time of mobile read-only transactions is greatly shortened. The tolerance of mobile transactions of disconnections from the broadcast channel is increased. In global validation mobile distributed transactions have to do check to ensure distributed serializability in all participants. The simulation results show that the new concurrency control protocol proposed offers better performance than other protocols in terms of miss rate, restart rate, commit rate. Under high work load (think time is ls) the miss rate of DMVOCC-MVDA is only 14.6%, is significantly lower than that of other protocols. The restart rate of DMVOCC-MVDA is only 32.3%, showing that DMVOCC-MVDA can effectively reduce the restart rate of mobile transactions. And the commit rate of DMVOCC-MVDA is up to 61.2%, which is obviously higher than that of other protocols. 展开更多
关键词 mobile distributed real-time database systems muliversion optimistic concurrency control multiversion dynamic adjustment pre-validation multiversion data broadcast
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