RESEARCH ON INFORMATION INTEGRATION SYSTEM BASED ON INCOMPLETE DATABASE CONCEPT

基于不完备数据库概念的信息集成系统研究

基本信息

批准号：
11680421
负责人：
MIYAZAKI Nobuyoshi
金额：
$ 1.79万
依托单位：
CHIBA INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680421/
关键词：
INCOMPLETE DATABASE INTEGRATED QUERY PROCESSING RETRIEVAL COMPRESSION TWO STAGE COMPRESSION

项目摘要

The aim of the project is to study the foundation and implementation techniques of information integration systems that process various databases scattered over open environment such as the Internet. Each database in an open environment is considered as an incomplete database which stores a part of a virtual database that consists of various databases. It is necessary to develop an efficient method to retrieve data in many sites which store data in various forms including compressed data. Search engines store data in compressed forms, and they use indices in order to efficiently search necessary data. It is important to consider both efficiency of search and compression ratio in these systems.Integrated query processing is realized based on incomplete database concepts, and it is possible to implement an incomplete database system using an existing database system. The method to construct such a system is investigated by implementing an experimental system. A compression method called the two stage compression method is also proposed and studied in order to reduce storage and to realize efficient search of globally scattered information. This method combines index-based compression and another ordinary compression method, and it is possible to efficiently retrieve data without compromising compression ratio.The performance of the two stage compression method is studied by implementing and measuring its performance. The performance of the method can be improved by adopting integrated indices instead of individual indices. The method was evaluated using data of newspapers and magazines, and was improved by variable code size. It is also found that the compression ratio of the method greatly varies when ordinary compression algorithm used in it is chaned.

该项目的目的是研究信息集成系统的基础和实施技术，这些系统处理各种数据库（例如互联网）。开放环境中的每个数据库都被视为一个不完整的数据库，该数据库存储由各种数据库组成的虚拟数据库的一部分。有必要开发一种有效的方法来检索许多位点，这些网站以各种形式存储在内的数据，包括压缩数据。搜索引擎以压缩形式存储数据，并使用索引来有效地搜索必要的数据。重要的是要考虑这些系统中的搜索效率和压缩率。集成查询处理是基于不完整的数据库概念实现的，并且可以使用现有数据库系统实现不完整的数据库系统。通过实施实验系统研究了构建此类系统的方法。还提出了一种称为“两个阶段压缩方法”的压缩方法，以减少存储并实现对全球分散信息的有效搜索。该方法结合了基于索引的压缩和另一种普通压缩方法，并且可以在不损害压缩比的情况下有效检索数据。通过实现和衡量其性能，研究了两个阶段压缩方法的性能。通过采用集成索引而不是单个指数，可以改善该方法的性能。使用报纸和杂志的数据评估了该方法，并通过可变代码大小改进了该方法。还发现，当将其使用中的普通压缩算法时，该方法的压缩率有很大变化。