共查询到18条相似文献,搜索用时 78 毫秒
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互关联后继树模型及其实现 总被引:6,自引:0,他引:6
全文检索是文本数据库研究的核心,而全文检索的首要问题是全文检索模型的选择。本文介绍了一种新颖的全文检索模型——互关联后继树模型及其实现,并将该模型与传统的倒排表模型进行了比较,发现它在各方面的性能均优于倒排表模型。 相似文献
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全文检索系统的重心是全文索引,全文检索的动态性取决于全文索引创建和更新的动态性.本文在对互关联后继树模型研究的基础上,借用操作系统和数据库的实现思想,对互关联后继树模型的存储结构进行优化,提高了索引更新的灵活性.文中给出了该结构的详细设计并提出了基于该结构的操作算法.实验证明,独特的结构很好地解决了索引的更新问题,较好地满足了数据频繁变化的应用需求. 相似文献
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本文介绍了一种新的全文数据库的数据模型——三元互关联后继树,并探讨其在呈现指数增长的非结构化的海量信息的存储和检索中的应用。 相似文献
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全文检索是一种非常有效的信息检索技术,本文通过分析全文检索系统中静态索引技术的优缺点,以及影响动态性能的因素,提出一种基于互关联后继树模型的动态索引技术,该技术在不影响查询效率等性能的情况下,很好地解决了索引的更新问题,提高了索引的动态性能。 相似文献
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全文检索是一种非常有效的信息检索技术,本文通过分析全文检索系统中静态索引技术的优缺点,以及影响动态性能的因素,提出一种基于互关联后继树模型的动态索引技术,该技术在不影响查询效率等性能的情况下,很好地解决了索引的更新问题,提高了索引的动态性能。 相似文献
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一个改进的互关联后继树数据模型 总被引:3,自引:1,他引:3
介绍了一种新型的全文数据库模型——互关联后继树,阐述它与其它全文数据库模型相比在呈现非结构化信息的存储和检索中的巨大优势,并探讨了面对呈现指数增长的非结构化的海量信息时如何提高其性能。 相似文献
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针对全文检索领域的索引结构模型的研究,基于三元互关联后继树模型,提出并实现了一个存储结构良好的索引系统.利用该系统实现了多种有效的查询. 相似文献
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二元互关联后继树精简索引模型研究 总被引:1,自引:0,他引:1
全文检索领域的关键问题是索引模型以及索引的创建与检索算法.基于二元互关联后继树模型,提出一个实用性能好的后继节点有序的后继树精简索引模型(SIRST),并给出此模型下索引的创建与检索算法.通过将该模型与使用广泛的倒排文件模型(IF)进行比较,表明SIRST的检索效率远远高于IF,同时,随着文本集规模越来越大,SIRST的创建效率优势愈发明显. 相似文献
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在全文检索中,要使索引具有较好的灵活性,就需有合适的索引结构及更新策略,使得既能有效地实现索引更新,又不影响查询效率.本文设计了一种基于互关联后继树模型的动态更新的索引结构,该索引结构由主索引、附加索引和删除文件列表组成,很好的解决了索引的更新问题. 相似文献
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As a important application of the Full-Text retrieval system, document relevancy has powerful function. In this paper, a document relevancy method based on the Full-Text retrieval system is presented, which is deeply discussed from two aspects, content relevancy and properties relevancy. This system is proved to have good response time and precision by tests. It has great prospects in application area. 相似文献
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采用hibernate search技术和lucene技术,设计和实现了基于数据库的站内全文搜索引擎。与基于关键字的搜索和网页搜索相比,能够对搜索内容进行细粒度的搜索控制,查全率和效率也有提高。 相似文献
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Our research extends the bit-sliced signature organization by introducing a partial evaluation approach for queries. The partial evaluation approach minimizes the response time by using a subset of the on-bits of the query signature. A new signature file optimization method, Partially evaluated Bit-Sliced Signature File (P-BSSF), for multi-term query environments using the partial evaluation approach is introduced. The analysis shows that, with 14% increase in space overhead, P-BSSF provides a query processing time improvement of more than 85% for multi-term query environments with respect to the best performance of the bit-sliced signature file (BSSF) method. Under the sequentiality assumption of disk blocks, P-BSSF provides a desirable response time of 1 second for a database size of one million records with a 28% space overhead. Due to partial evaluation, the desirable response time is guaranteed for queries with several terms. 相似文献
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Text retrieval systems require an index to allow efficient retrieval of documents at the cost of some storage overhead. This paper proposes a novel full-text indexing model for Chinese text retrieval based on the concept of adjacency matrix of directed graph. Using this indexing model, on one hand, retrieval systems need to keep only the indexing data, instead of the indexing data and the original text data as the traditional retrieval systems always do. On the other hand, occurrences of index term are identified by labels of the so-called s-strings where the index term appears, rather than by its positions as in traditional indexing models. Consequently, system space cost as a whole can be reduced drastically while retrieval efficiency is maintained satisfactory. Experiments over several real-world Chinese text collections are carried out to demonstrate the effectiveness and efficiency of this model. In addition to Chinese, The proposed indexing model is also effective and efficient for text retrieval of other Oriental languages, such as Japanese and Korean. It is especially useful for digital library application areas where storage resource is very limited (e.g., e-books and CD-based text retrieval systems). 相似文献