A straightforward NF2 relational interface with applications in information retrieval

Niemi, Timo; Järvelin, Kalervo

doi:10.1016/0306-4573(94)00040-a

Cited by 11 publications

(9 citation statements)

References 17 publications

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“…Our purpose is to find those factors that facilitate query formulation considerably from the view point of the user. We have developed query languages and techniques for their implementation in terms of which specification related to navigation [14][15] and restructuring [27][28] among data can be removed from the user. Likewise we have shown that in deductive databases complex recursive rule definitions for transitive processing can be replaced by a set of operations intuitive to the user [24][25].…”

Section: Discussionmentioning

confidence: 99%

Query language approach based on the deductive object-oriented database paradigm

Niemi

Christensen

Järvelin

2000

Information and Software Technology

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Section: Discussionmentioning

confidence: 99%

Query language approach based on the deductive object-oriented database paradigm

Niemi

Christensen

Järvelin

2000

Information and Software Technology

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“…The second problem is that query formulation in NF 2 is complicated because the nested relations must be unnested before actual query formulation. Niemi and Järvelin [4] show in detail why nesting and unnesting complicate query formulation. Our approach is not based on NF 2 relations, but on a general purpose relational database where hierarchical data structures are represented by ordinary relations and foreign key constraints.…”

Section: Related Workmentioning

confidence: 99%

“…Manipulation of hierarchical part-of/aggregate structures plays a central role in several application domains such as physical assemblies [1], medicine information systems [2], geographical information systems [3] and informatics [4]. The importance of the part-of structures has also been noticed in early semantic data models [5], as in modern software design methods [6].…”

Section: Introductionmentioning

confidence: 99%

SQL-based semantics for path expressions over hierarchical data in relational databases

Vainio

Junkkari

2014

Journal of Information Science

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Hierarchical part-of relationships/aggregation structures and related queries are essential parts of information systems. However, relational database query languages do not explicitly support hierarchical relationships and queries. A hierarchical query may require a great number of join operations, which increases the effort in query formulation. Therefore, we propose path expressions in formulating hierarchical views over relational data because path expressions are a conventional and compact way to represent hierarchical relationships. We embed path expressions within SQL queries and compile them to standard SQL. This ensures that the path expressions can straightforwardly be implemented on the top of standard relational database systems. The compilation of a path expression is given by an attribute grammar, a conventional formalism to define the semantics of a language.

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“…articles by journals or by institutions. Therefore a mechanism for restructuring the hierarchical relationships among subdocuments into new result documents is needed [25], e.g. articles by domains.…”

Section: Aslib the Association For Information Managementmentioning

confidence: 99%

A user‐oriented interface for generalised informetric analysis based on applying advanced data modelling techniques

Järvelin

Ingwersen²,

Niemi³

2000

Journal of Documentation

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This article presents a novel user‐oriented interface for generalised informetric analysis and demonstrates how informetric calculations can easily and declaratively be specified through advanced data modelling techniques. The interface is declarative and at a high level. Therefore it is easy to use, flexible and extensible. It enables end users to perform basic informetric ad hoc calculations easily and often with much less effort than in contemporary online retrieval systems. It also provides several fruitful generalisations of typical informetric measurements like impact factors. These are based on substituting traditional foci of analysis, for instance journals, by other object types, such as authors, organisations or countries. In the interface, bibliographic data are modelled as complex objects (non‐first normal form relations) and terminological and citation networks involving transitive relationships are modelled as binary relations for deductive processing. The interface is flexible, because it makes it easy to switch focus between various object types for informetric calculations, e.g. from authors to institutions. Moreover, it is demonstrated that all informetric data can easily be broken down by criteria that foster advanced analysis, e.g. by years or content‐bearing attributes. Such modelling allows flexible data aggregation along many dimensions. These salient features emerge from the query interface‘s general data restructuring and aggregation capabilities combined with transitive processing capabilities. The features are illustrated by means of sample queries and results in the article.

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A straightforward NF2 relational interface with applications in information retrieval

Cited by 11 publications

References 17 publications

Query language approach based on the deductive object-oriented database paradigm

Query language approach based on the deductive object-oriented database paradigm

SQL-based semantics for path expressions over hierarchical data in relational databases

A user‐oriented interface for generalised informetric analysis based on applying advanced data modelling techniques

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