Using the whole image and restrictions in the research of properties of some signature operations in Table Algebra

2019 ◽  
Vol 33 ◽  
pp. 112-121
Author(s):  
Nadiya Kakhuta ◽  
Alexey Senchenko
Keyword(s):  
Binary Relation ◽  
Relational Databases ◽  
Query Language ◽  
Relational Algebra ◽  
General Interest ◽  
Table Algebras ◽  
Modern Analogue ◽  
Table Data ◽  
Table Algebra ◽  
Composition Of Relations

The features of the whole image relative to many binary relation, and restrictions on a binary relation on the set for some of the signature operations of Table Algebra are used in the work. Constructions of the whole image and restrictions are of general interest for Mathematics, and Table Algebra is a modern analogue of Codd's well-known Relational Algebra. It forms the theoretical foundation of modern query language databases. Elements of the carrier of Table Algebra specify relational table data structures, and signature operations are based on the basic table manipulations in Relational Algebra and SQL-like languages. The following results in the research of the features of the whole image were obtained: interconnections between the whole image and restrictions were found; the monotony and distribution of the whole image and restrictions on unions, a criterion of their emptiness and interconnections with first and second projection relations were proved; the whole image of the composition of relations and composition restrictions were found; the distribution of restriction on intersection of sets was set; the estimates of the distribution of the whole image of intersection and difference of sets were given; criteria for distribution of the whole image relative to the intersection and differences of sets were found. In addition, the clues were provided with the help of the whole image and restrictions on some of the signature operations of Table Algebra: intersection, union, difference, projection and joining. These representations allowed us to obtain some features of these operations, which derive directly from the features of the whole image and restrictions. It is supposed to get similar views on other signature operations of Table Algebras and to allocate their features arising from such representation. The obtained results can be used in the theory of Table Algebra as an approach to the research of the features of their signature operations, this can be used in query optimization in relational databases.

scholarly journals The interrelations between intersection, union and other signature operations in table algebra

2018 ◽  
Vol 32 ◽  
pp. 121-132 ◽  
Author(s):  
Alexey Senchenko
Keyword(s):  
Relational Database ◽  
Query Language ◽  
Standard Form ◽  
Point Of View ◽  
Relational Algebra ◽  
Equivalent Transformation ◽  
Table Algebras ◽  
Finite Set ◽  
Table Algebra ◽  
Almost All

Currently, databases are widely used in almost all areas of human activity. For all variety of different types of databases the most common are relational (table) databases, mathematical model of which was proposed by E. Codd. From mathematical point of view, a relational database is a finite set of finite relations between different predefined sets of basic data. Table algebra introduced by V.N. Red’ko and D.B. Buy is based on Codd’s relational algebra and significantly improves it. It formed the theoretical foundation of modern database query language. Elements of the carrier of table algebra specify relational data structures, and signature operations are based on the basic table manipulations in relational algebra and SQL-like languages. One of the most actual tasks in relational and table algebras is the problem of equivalent transformation of expressions in order to minimize or reduce them to a standard form; it is one of the stages of query optimization, and can also significantly reduce the processing time of information in relational database management systems. For the decision of this problem the interrelations between the basic table operations are used. In the present, a significant number of such interrelations have been established, most of which for the general case are performed as inclusions. The author has found criteria for the transition of some such inclusions into equalities. These criteria are expressed in terms of the active domains of the tables and are natural. In this paper, the interrelations of the intersection and the union of tables with other signature operations of table algebras: difference, selection, projection, saturation, active complement, join, renaming of attributes are considered.

A Temporal Query System for Protocol-Directed Decision Support

1994 ◽  
Vol 33 (04) ◽  
pp. 358-370 ◽  
Author(s):  
A. K. Das ◽  
M. A. Musen
Keyword(s):  
Decision Support ◽  
Relational Databases ◽  
Query Language ◽  
Search Time ◽  
Relational Algebra ◽  
Temporal Data ◽  
Relational Data Model ◽  
Temporal Query ◽  
Query System ◽  
Temporal Algebra

Abstract:Chronus is a query system that supports temporal extensions to the Structured Query Language (SQL) for relational databases. Although the relational data model can store time-stamped data and can permit simple temporal-comparison operations, it does not provide either a closed or a sufficient algebra for manipulating temporal data. In this paper, we outline an algebra that maintains a consistent relational representation of temporal data and that allows the type of temporal queries needed for protocol-directed decision support. We also discuss how Chronus can translate between our temporal algebra and the relational algebra used for SQL queries. We have applied our system to the task of screening patients for clinical trials. Our results demonstrate that Chronus can express sufficiently all required temporal queries, and that the search time of such queries is similar to that of standard SQL.

GuessXQ

2013 ◽  
pp. 57-76
Author(s):  
Daniela Morais Fonte ◽  
Daniela da Cruz ◽  
Pedro Rangel Henriques ◽  
Alda Lopes Gancarski
Keyword(s):  
Information Retrieval ◽  
Learning Process ◽  
Web Application ◽  
Relational Databases ◽  
Query Language ◽  
General Purpose ◽  
Considerable Effort ◽  
Document Structure ◽  
Query By Example ◽  
Xml Documents

XML is a widely used general-purpose annotation formalism for creating custom markup languages. XML annotations give structure to plain documents to interpret their content. To extract information from XML documents XPath and XQuery languages can be used. However, the learning of these dialects requires a considerable effort. In this context, the traditional Query-By-Example methodology (for Relational Databases) can be an important contribution to leverage this learning process, freeing the user from knowing the specific query language details or even the document structure. This chapter describes how to apply the Query-By-Example concept in a Web-application for information retrieval from XML documents, the GuessXQ system. This engine is capable of deducing, from an example, the respective XQuery statement. The example consists of marking the desired components directly on a sample document, picked-up from a collection. After inferring the corresponding query, GuessXQ applies it to the collection to obtain the desired result.

Web Services as XML Data Sources in Enterprise Information Integration

2011 ◽  
pp. 972-985
Author(s):  
Ákos Hajnal ◽  
Tamás Kifor ◽  
Gergely Lukácsy ◽  
László Z. Varga
Keyword(s):  
Web Services ◽  
Web Service ◽  
Information Integration ◽  
Digital Libraries ◽  
Relational Databases ◽  
Query Language ◽  
Data Sources ◽  
Enterprise Information ◽  
Xml Data ◽  
The Web

More and more systems provide data through web service interfaces and these data have to be integrated with the legacy relational databases of the enterprise. The integration is usually done with enterprise information integration systems which provide a uniform query language to all information sources, therefore the XML data sources of Web services having a procedural access interface have to be matched with relational data sources having a database interface. In this chapter the authors provide a solution to this problem by describing the Web service wrapper component of the SINTAGMA Enterprise Information Integration system. They demonstrate Web services as XML data sources in enterprise information integration by showing how the web service wrapper component integrates XML data of Web services in the application domain of digital libraries.

USING FRINGES FOR MINIMAL CONCEPTUAL DECOMPOSITION OF BINARY CONTEXTS

2012 ◽  
Vol 08 (03) ◽  
pp. 385-394 ◽  
Author(s):  
ALI JAOUA ◽  
MOHAMED SALAH ◽  
SADOK BEN YAHIA ◽  
JIHAD M. AL-JA'AM
Keyword(s):  
Binary Relation ◽  
Real Data ◽  
Relational Algebra ◽  
Formal Context ◽  
Formal Concept ◽  
Decomposition Algorithms ◽  
Huge Data ◽  
Formal Concepts ◽  
Np Complete ◽  
Formal Properties

Extracting knowledge from huge data in a reasonable time is still a challenging problem. Most real data (structured or not) can be mapped to an equivalent binary context, with or without using a scaling method, as for extracting associations between words in a text, or in machine learning systems. In this paper, our objective is to find a minimal coverage of a relation [Formula: see text] with formal concepts. The problem is known to be NP-complete.1 In this paper, we exploit a particular difunctional relation embedded in any binary relation [Formula: see text], the fringe of [Formula: see text], to find an approximate conceptual coverage of [Formula: see text]. We use formal properties of fringes to find better algorithms calculating the minimal rectangular coverage of binary relation. Here, a formal context is considered as a binary relation. By exploiting some background on relational algebra in the present work, we merge some results of Belohlavek and Vichodyl,2 using formal concept analysis with previous results obtained by Kcherif et al.3 using relational algebra. We finally propose decomposition algorithms based on the relational formalization and fringe relations.

The Design of Web User Interface Based on Dynamic Re-Components

2014 ◽  
Vol 539 ◽  
pp. 424-428
Author(s):  
Shi Liu ◽  
Jia Lin Gang ◽  
He Ma
Keyword(s):  
User Interface ◽  
Interface Design ◽  
Web Application ◽  
Relational Databases ◽  
Structural Changes ◽  
Web Application System ◽  
Display Function ◽  
Web Interface Design ◽  
Table Data ◽  
Flexible Component

For environment and user needs easy-to-change issues in the Web application system application, the ideology of flexible software and Web interface design combining in the paper, we proposed a dynamic reconfiguration capability flexible component-based Web user interface model. The model displays the description of component style templates and adapts to the structural changes of business data component rules stored in the XML documents and relational databases, so as to solve the adaptability and reusability of Web user interface. Finally, a flexible Web user interface of the table data display function to illustrate the effectiveness and availability of the model.

scholarly journals Automated Generation of Personal Data Reports from Relational Databases

2011 ◽  
Vol 10 (02) ◽  
pp. 193-208 ◽  
Author(s):  
Georgios John Fakas ◽  
Ben Cawley ◽  
Zhi Cai
Keyword(s):  
Prior Knowledge ◽  
Data Protection ◽  
Relational Databases ◽  
Query Language ◽  
Personal Data ◽  
Query Languages ◽  
Hash Tables ◽  
Automated Generation ◽  
Novel Approach ◽  
Performance Results

This paper presents a novel approach for extracting personal data and automatically generating Personal Data Reports (PDRs) from relational databases. Such PDRs can be used among other purposes for compliance with Subject Access Requests of Data Protection Acts. Two methodologies with different usability characteristics are introduced: (1) the GDSBased Method and (2) the By Schema Browsing Method. The proposed methdologies combine the use of graphs and query languages for the construction of PDRs. The novelty of these methodologies is that they do not require any prior knowledge of either the database schema or of any query language by the users. An optimisation algorithm is proposed that employs Hash Tables and reuses already found data. We conducted several queries on two standard benchmark databases (i.e. TPC-H and Microsoft Northwind) and we present the performance results.

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