Information In Relational Databases Research Articles

An efficient retrieval of relational database information based on knowledge graph

An efficient retrieval of relational database information based on knowledge graph

An efficient retrieval of relational database information based on knowledge graph

An efficient retrieval of relational database information based on knowledge graph

Querying incomplete information in RDF with SPARQL

Incomplete information has been studied in-depth in relational databases and knowledge representation. In the context of the Web, incomplete information issues have been studied in detail for XML, but very few papers exist that do the same for RDF. In this paper we make the first general proposal for extending RDF with the ability to represent property values that exist but are unknown or partially known using constraints. Following ideas from incomplete information literature, we develop a semantics for this extension of RDF, called RDFi, and study query evaluation for SPARQL. We transfer the concept of representation systems from incomplete information in relational databases to the case of RDFi and identify two very important fragments of SPARQL that can be used to define a representation system for RDFi. The first corresponds to the monotone fragment of graph patterns that uses only the operators AND, UNION, and FILTER. The second corresponds to the well-designed graph patterns, that is, a fragment that uses only operators AND, FILTER, and OPT, and enjoys interesting properties that make query evaluation efficient. We prove that each of the two fragments can be used to define a representation system for CONSTRUCT queries without blank nodes in their templates. We also define the fundamental concept of certain answers to SPARQL queries over RDFi databases and present an algorithm for its computation. Then, we present complexity results for computing certain answers by considering equality, temporal, and spatial constraint languages and the class of CONSTRUCT queries of our representation systems. Finally, we demonstrate the usefulness of RDFi in geospatial Semantic Web applications by giving a number of examples and comparing the modeling capabilities of RDFi with related formalisms found in the literature.

Annotating database schemas to help enterprise search

In large enterprises, data discovery is a common problem faced by users who need to find relevant information in relational databases. In this scenario, schema annotation is a useful tool to enrich a database schema with descriptive keywords. In this paper, we demonstrate Barcelos, a system that automatically annotates corporate databases. Unlike existing annotation approaches that use Web oriented knowledge bases, Barcelos mines enterprise spreadsheets to find candidate annotations. Our experimental evaluation shows that Barcelos produces high quality annotations; the top-5 have an average precision of 87%.

The Pathway Editor: A tool for managing complex biological networks

Biological networks are systems of biochemical processes inside a cell that involve cellular constituents such as DNA, RNA, proteins, and various small molecules. Pathway maps are often used to represent the structure of such networks with associated biological information. Several pathway editors exist, and they vary according to specific domains of knowledge. This paper presents a review of existing pathway editors, along with an introduction to the Edinburgh Pathway Editor (EPE). EPE was designed for the annotation, visualization, and presentation of a wide variety of biological networks that include metabolic, genetic, and signal transduction pathways. EPE is based on a metadata-driven architecture. The editor supports the presentation and annotation of maps, in addition to the storage and retrieval of reaction kinetics information in relational databases that are either local or remote. EPE also has facilities for linking graphical objects to external databases and Web resources, and is capable of reproducing most existing graphical notations and visual representations of pathway maps. In summary, EPE provides a highly flexible tool for combining visualization, editing, and database manipulation of information relating to biological networks. EPE is open-source software, distributed under the Eclipse open-source application platform license.

MetaBasis

We have developed an integrated web-based relational database information system, which offers an extensive search functionality of validated entries containing available bioinformatics computing resources. This system, called MetaBasis, aims to provide the bioinformatics community, and especially newcomers to the field, with easy access to reliable bioinformatics databases and tools. MetaBasis is focused on non-commercial and open-source software tools. http://metabasis.bioacademy.gr/

A tree for rocks—hierarchies in stratigraphic databases

In this paper we present a new data model for a computer-supported management of stratigraphic information in relational databases, with special consideration to the hierarchical order of stratigraphic units. The huge amount of data on stratigraphic units provided by earth scientists during the last decades requires data models which—besides names, ages and background information such as used taxa in biostratigraphic units—can store both the position of a single unit within a stratigraphic column as well as its position within the stratigraphic hierarchy. The hierarchy management in the present data model is based on a modification of the nested-set data model, which is the core of the stratigraphy.net stratigraphic database system ( http://www.stratigraphy.net). The nested-set data model allows one to store alternative classifications of stratigraphic units with theoretically unlimited number of tree levels and unlimited amount of tree elements. Multiple hierarchies based on different disciplines such as biostratigraphy or lithostratigraphy can be stored in databases using the model presented here. In comparison to other models, the modified nested-set data model allows a high query performance. It permits an almost unlimited flexibility in describing the complex nature of stratigraphical information without limitations in the definition of standard query language queries. The application of this model is presented with detailed examples from the stratigraphy.net database.

관계형 데이터베이스 기반의 XML 응용을 위한, UML 클래스를 이용한 통합 설계 방법론

B2B 전자상거래와 같이 XML을 이용한 정보 교환이 확산되고 있으며 이에 따라 상호 교환되는 정보에 대하여 체계적이며 안정적인 저장관리가 요구되고 있다. 이를 위해 XML 응용과 데이터베이스 연계를 위한 다양한 연구가 관계형 데이터베이스를 중심으로 수행되었다. 그러나 계층구조를 갖는 XML 데이터를 2차원 테이블의 집합인 관계형 정보로 표현하는 관계형 데이터베이스로의 저장에는 본질적인 한계가 있어, 계층적 구조를 2차원 정보로 변환하는 방법에 의해서 각 구조화된 정보를 관계형 데이터베이스로 저장하기 위한 모델링 방안이 요구된다. 양질의 어플리케이션 시스템을 구축하기 위해서는 우선적으로 모델링이 중요하다. 1997년에 OMG는 표준 모델링 언어로 UML를 채택하였고, 이에 따라 UML은 보다 널리 사용될 것이다. 그러므로 효율적인 XML 어플리케이션을 개발하는데 UML에 기반을 둔 설계 방법론이 필요하다고 할 수 있다. 본 논문에서는 UML을 이용한, 관계형 데이터베이스기반의 XML 응용을 위한 통합 설계 방법론을 제안한다. 이를 위하여 먼저 UML을 이용하여 W3C XML schema를 설계하기 위한 XML 모델링 방안을 제시하고, 아울러 교환되는 XML 데이터를 효율적으로 저장하기 위하여 관계형 데이터베이스 스키마 설계를 위한 데이터 모델링 방법을 제안한다. Nowadays the information exchange based on XML such as B2B electronic commerce is spreading. Therefore a systematic and stable management mechanism for storing the exchanged information is needed. For this goal there are many research activities for concerning the connection between XML application and relational databases. But because XML data has hierarchical structure and relational databases can store only flat-structured data, we need to make a conversion rule which changes the hierarchical architecture to a 2-dimensional format. Accordingly the modeling methodology for storing such structured information in relational databases is needed. In order to build good quality application systems, modeling is an important first step. In 1997, the OMG adopted the UML as its standard modeling language. Since industry has warmly embraced UML, its popularity should become more important in the future. So a design methodology based on UML is needed to develop efficient XML applications. In this paper, we propose a unified design methodology for XML applications based on relational database using UML. To reach these goals, first we introduce a XML modeling methodology to design W3C XML schema using UML and second we propose data modeling methodology for relational database schema to store XML data efficiently in relational databases.

Efficient representation and algebraic manipulation of infinite relations in paraconsistent databases

Paraconsistent information is information that is incomplete and/or inconsistent. A data model for handling paraconsistent information in relational databases has recently been developed. In this paper, we show that a DBMS based on paraconsistent relations must be capable of handling infinite relations. We also identify classes of infinite paraconsistent relations whose members can be effectively represented and manipulated. We show that the classes of REGULAR and, under different conditions, CONTEXT-SENSITIVE as well as PSPACE paraconsistent relations are such. We also show that the CONTEXT-FREE and R.E. classes do not have the desired properties, while P, NP, LOGSPACE and NLOGSPACE also probably do not. These results help identify the kinds of relational DBMS that can be constructed for handling incomplete and inconsistent information about tuples. We finally show that all operations for the aforementioned PSPACE and CONTEXT-SENSITIVE cases can be carried out efficiently in polynomial time.

The Impact of Single Versus Dual Data Entry on Accuracy of Relational Database Information

Objective: To evaluate the differences in entry errors associated with entry of prospective cohort data using a single versus a dual data entry system. Design: Cross-over trial Measurements: The database for the Canadian Intercollegiate Sport Injury Registry (CISIR) has, to date, used a dual data entry system. To test the differences in entry error, one season of injury and exposure (participation) data were entered for one sport from two participating institutions. A total of 5 data entry clerks were involved. Discrepancies between the final entries from both systems were flagged and checked against the original paper record. The number of instances where the dual entry system was correct but the single entry system was incorrect, and vice versa, were determined. Results: A total of 17,988 database fields were evaluated (15,509 text and 2,479 fixed response fields). There was a statistically significant difference in error where the dual entry system was correct but the single entry system was incorrect for 2 out of the 4 data entry modules. The percent accuracy using the single entry system was lower (99.35%) than that using the dual entry system (99.83%). Conclusions: Although the single entry system was statistically different from the dual entry system, the percent accuracy remained high and the errors did not cluster in one specific field. Given the doubling of entry costs with a dual entry system, it is recommended that a single entry system be used for the CISIR.

A multi-user real time inventorying system for radioactive materials: a networking approach.

A computerized system for radioisotope management and real time inventory coordinated across a large organization is reported. It handles hundreds of individual users and their separate inventory records. Use of highly efficient computer network and database technologies makes it possible to accept, maintain, and furnish all records related to receipt, usage, and disposal of the radioactive materials for the users separately and collectively. The system's central processor is an HP-9000/800 G60 RISC server and users from across the organization use their personal computers to login to this server using the TCP/IP networking protocol, which makes distributed use of the system possible. Radioisotope decay is automatically calculated by the program, so that it can make the up-to-date radioisotope inventory data of an entire institution available immediately. The system is specifically designed to allow use by large numbers of users (about 300) and accommodates high volumes of data input and retrieval without compromising simplicity and accuracy. Overall, it is an example of a true multi-user, on-line, relational database information system that makes the functioning of a radiation safety department efficient.

ABC of Medical Computing: STORING AND MANAGING DATA ON A COMPUTER

All readers will be familiar with the traditional card index which is used to store relatively simple information such as a list of books in a library. Database programs are the electronic equivalent of a card index but offer several advantages. Most important of these is the ability to search and analyse the stored data rapidly and reliably. In addition to this, large amounts of information can be stored in a fraction of the space that would be required for equivalent paper records; several people on a network or multiuser system can use the same database simultaneously; and the results of searches can easily be printed in the form of a report. Furthermore, any stored data can be used by other programs such as a word processor (for creating circular letters or mailing labels), a spreadsheet (for manipulation and charting of the data), or a statistical program (for detailed analysis). Information stored in a database is broken down into manageable portions which are stored in separate compartments called fields and records. For example, a surname would be entered into one field, and the first name or initial and date of birth into subsequent fields. A collection of fields relating to one person or event is called a record. A database can contain an unlimited number of records. Flatfile databases are the most basic type and are analogous to a card index. They are easy to create with any database program and are ideal for storing simple information such as a list of names and addresses. They offer all the facilities that many people are likely to need. Simple flatfile database. In a relational database information is stored in several separate, cross referenced database files. Although more complex, this structure allows very powerful and efficient systems to be developed. A good …

Error-correcting code for volume holographic storage of a relational database

We present an error-correcting code suitable for encoding relational database information to be stored in a volume holographic memory system. The code makes use of the page-oriented format of holographic memories as well as the tabular arrangement of database records. The performance metrics discussed here show that the code results in industry-standard bit error rates and permits simple and fast decoding.

A prototype rule-based front end expert system for integrity enforcement in relational data bases: An application to the naval aircraft flight records data base

An important goal of any data base system is to model the real world accurately in a manner consistent with the user's perception of the data. One way to accomplish the accuracy of information in relational data bases is through the enforcement of integrity constraints that represent rules pertaining to the organization. Unfortunately, most DBMSs today do not provide adequate integrity features to ensure the accuracy of data in their databases. This paper discusses the design and implementation of a prototype rule-based front end expert system for integrity enforcement for the Naval Aircraft Flight Record relational data base. The expert system includes a set of rules that define (a) the update operation that triggers the testing of an integrity rule, (b) a specification of the condition to be tested, and (c) the action to be taken in case of attempted violation. These rules are stored in a knowledge base, which the inference engine of the expert system uses to enforce data base integrity.

A more general model for handling missing information in relational databases using a 3-valued logic

Codd proposed the use of two interpretations of nulls to handle missing information in relational databases that may lead to a 4-valued logic [Codd86, Codd87]. In a more general model, three interpretations of nulls are necessary [Roth, Zani]. Without simplification, this may lead to a 7-valued logic, which is too complicated to be adopted in relational databases. For such a model, there is no satisfactory simplification to a 4-valued logic. However, by making a straightforward simplification and using some proposed logical functions, a 3-valued logic can handle all three interpretations.

An extended version of the fuzzy relational database model

The fuzzy relational database model proposed by Buckles and Petry is a formal method for organizing and using fuzzy information in relational databases. The model possesses two key properties that hold for classical relational databases: no two tuples have identical interpretations and each relational algebra operation has a unique result. The original fuzzy relational database model was based on similarity relations which were defined on finite scalar domains. Buckles and Petry later extended the model to incorporate fuzzy number domains; this extension was done without loss of consistency with the representation or the relational algebra. In a recent paper we have extended the original model to proximity relations which generalize similarity relations; the key properties of Buckles and Petry's model are preserved in the extension. In this work we demonstrate that the existence of partitions on finite scalar domains in the fuzzy relational model is the key to preserving the important properties of the classical relational model. We explain how proximity relations defined on finite scalar domains are used to partition the domains. Further, we show that normal fuzzy sets can be employed as domain values. These fuzzy sets become members of fi nite scalar domains and their characteristic functions are employed in generating the proximity relations of the fuzzy relational database model.

Indefinite and maybe information in relational databases

This paper extends the relational model to represent indefinite and maybe kinds of incomplete information. A data structure, called an I-table, which is capable of representing indefinite and maybe facts, is introduced. The information content of I-tables is precisely defined, and an operator to remove redundant facts is presented. The relational algebra is then extended in a semantically correct way to operate on I-tables. Queries are posed in the same way as in conventional relational algebra; however, the user may now expect indefinite as well as maybe answers.

Partition semantics for incomplete information in relational databases

We define partition semantics for databases with incomplete information and we present an algorithm for query processing in the presence of incomplete information and functional dependencies. We show that Lipski's model for databases with incomplete information can be seen as a special case of our model.

A sound and complete query evaluation algorithm for relational databases with null values

Reiter has proposed extended relational theory to formulate relational databases with null values and presented a query evaluation algorithm for such databases. However, due to indefinite information brought in by null values, Reiter's algorithm is sound but not complete. In this paper, we first propose an extended relation to represent indefinite information in relational databases. Then, we define an extended relational algebra for extended relations. Based on Reiter's extended relational theory, and our extended relations and the extended relational algebra, we present a sound and complete query evaluation algorithm for relational databases with null values

Repetitive bibliographical information in relational databases

Bibliographical databases frequently have a few long, repetitive strings such as the recurring names of voluminous authors. Potter [Library Trends. 30(1): 21–39; 1981] observed this characteristic of bibliographical databases in his sample from the University of Illinois library catalog. This article presents a solution to the problem of loading repetitive bibliographical information in a microcomputer-based relational database-management system. Normalization theory does not explicitly address the characteristics of bibliographical relational databases. The representational redundancy design saves space in relational database tables by removing long, frequently occurring strings to separate tables where they can be referenced by shorter surrogates in a main table. This design was suggested by some reflections by Kent (Data and Reality, Basic Assumptions in Data Processing Reconsidered. Amsterdam: North-Holland; 1978) and by the example of MERLIN [Program. 10(4): 123–134; 1976]. Telephone-book data and the library-catalog data of Potter was used to illustrate the economies achieved in representing repetitive bibliographical information in relational databases. © 1988 John Wiley & Sons, Inc.