Evaluating database management systems : a framework and application to the Veteran's Administration Hospital.

Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Includes bibliographical references.M.S

CRITÉRIOS DE SELEÇÃO DE SGBD NOSQL EM ORGANIZAÇÕES BRASILEIRAS

The large volume of data generated by Web applications and the requirements of scalability and high degree of availability have contributed to the emergence of new models and technologies related to DBMS (Database Management Systems). In this environment of growing demand for data volume and performance, a new model of DBMS, called NoSQL arises. Within this context, this research aims to identify the main criteria that should be used for selecting a NoSQL DBMS in private organizations. We used a qualitative research based on the Delphi Technique. The application of this technique was carried out between January and March 2013, with the participation of 32 specialists. The research identified nine criteria that should be considered in the selection process of DBMS in private organizations.O grande volume de dados gerado por aplicações Web, juntamente com requisitos diferenciados, como a escalabilidade e o elevado grau de disponibilidade, têm contribuído para o surgimento de novos modelos e tecnologias com relação aos SGBDs (Sistemas Gerenciadores de Bancos de Dados). Neste ambiente de crescente demanda por volume de dados e desempenho, surge um novo modelo de SGBD, chamado NoSQL. Dentro desse contexto, esta pesquisa tem como objetivo identificar os principais critérios que devem ser usados para seleção de um SGBD NoSQL em organizações privadas. Utilizou-se uma pesquisa qualitativa baseada na Técnica Delphi. A aplicação dessa técnica foi realizada entre os meses de janeiro e março de 2013 com a participação de 32 especialistas. A pesquisa identificou nove critérios que devem ser considerados no processo de seleção de SGBD em organizações privadas

Database coverage in the accounting information system course in Malaysia

This paper reports the results of a survey that examines the extent of coverage of database management systems concept and topics in the undergraduate accounting information systems (AIS) course in Malaysian universities. Broad area surveyed are basic database terminology, database models, designing and optimizing a database, security and control of database systems, and implementation, administration and evaluation of database management systems. Bloom's taxonomy (Bloom, 1956) is used to asses the level of coverage of each topic.The results show that despite the 1986 recommendations of the AAA Committee on Contemporary Approaches to Teaching AIS and recent changes in the accounting profession, it appears that large numbers of Malaysian universities are not covering fundamental concepts and topics in the area of database management systems.On the other hand, the level of coverage is relatively high among those universities which incorporate database concepts and topics into their AIS courses where more than 60 percent of the items are covered at the analysis level and above.This trend seem to be parallel with the growth of information technology and increasing importance of database tools and techniques in practise

Digital image processing and isostatic studies of the regional gravity field of Great Britain and adjacent marine regions

This thesis presents the results of an investigation into the regional gravity field of Great Britain and the adjacent regions. A prerequisite for this study was the development of a computer database designed to store, manipulate and display the information contained within nearly 400,000 gravity and topography point observations for the region. Digital image processing techniques have been applied to the reduction and display of the Bouguer anomaly data. The observed Bouguer anomaly lineaments display a pattern of geological basement structures which correlates closely with those predicted by recent plate tectonic models of the Lower Palaeozoic Caledonian orogeny which assume the convergence of three distinct continental plates. The nature of the isostatic compensation of the topography in the vicinity of the United Kingdom has been investigated using cross spectral analysis of the gravity and topography. The observed cross spectral relationships are compared with those for a theoretical isostatic model which assumes the lithosphere behaves like a thin elastic plate loaded by both surface topography and internal density contrasts overlying an inviscid fluid substratum. For a uniform elastic thickness of the continental lithosphere the best fit between the observed and theoretical relationships is obtained for values of the elastic thickness of the lithosphere of 22.5-24.5 km. A better fit is obtained if the continental lithosphere is assumed to comprise a population of distinct tectonic provinces of equal area with the values of the elastic thickness of the lithosphere for the provinces distributed uniformly between 6-8 km and 86-90 km. Detailed investigations into the structure of the crust beneath the Tertiary igneous complexes of Mull and Skye, northwest Scotland, indicate a possible slight thickening of the crust which is considered to be an important consequence of the mechanism of the emplacement of the complexes

Persistência Poliglota - Diferentes Necessidades de Armazenamento de Dados

A necessidade crescente de se armazenarem grandes quantidades de dados, de forma a prover serviços escaláveis, obrigou à procura de novas soluções, ao longo do tempo. No decurso da história podem enumerar-se diversos sistemas de dados: o hierárquico, o em rede, o relacional, o orientado a objetos, o objeto-relacional e, mais recentemente, o NoSQL. Todos estes sistemas tentaram dar resposta a diferentes realidades do armazenamento de dados, indo ao encontro dos problemas de cada época. Devido à necessidade de se aproveitarem as vantagens que cada tipo de base de dados oferece, surgiu o conceito de Persistência Poliglota, que traduz a integração de vários tipos de bases de dados num só sistema. Esta abordagem tem como objetivo retirar o melhor de cada base de dados, apresentando uma solução fiável e alternativa aos sistemas com apenas um tipo de base de dados. Como tal, este trabalho visa a análise da abordagem de Persistência Poliglota para comparar sistemas compostos por diversos sistemas de gestão de base de dados versus os que utilizam apenas um motor de base de dados, de modo a verificar se esta abordagem é útil e vantajosa. Desta forma, elaborou-se uma prova de conceito, com base num problema proposto, com o objetivo de se analisarem dois sistemas, um único e outro poliglota, tendo por base três volumes de dados diferentes. Para isto, foi necessário proceder-se à análise e escolha dos sistemas de gestão de base de dados a utilizar e montar os ambientes de teste, para ambos os sistemas. Com recurso a várias consultas individuais (a cada base de dados) e globais (conjunto das bases de dados que compõem o sistema poliglota), foram analisados os resultados obtidos com recurso à métrica de medição do desempenho relativa aos tempos de consulta. O trabalho e os resultados obtidos evidenciaram um aumento do desempenho, quanto à utilização individual das bases de dados. Perante o conjunto das bases de dados, apesar de um ligeiro aumento, nota-se que os resultados não são claros e que carecem de uma investigação mais profunda. Por fim, é possível afirmar que a abordagem poliglota é principalmente útil em sistemas complexos, onde o volume de dados é elevado, e onde se pretende armazenar diferentes tipos de dados.ABSTRACT: The increasing need to store large amounts of data in order to provide scalable services has forced the search for new solutions over time. In the course of history, several data systems can be enumerated: hierarchical, network, relational, object-oriented, object-relational, and, more recently, NoSQL. All these systems tried to respond to different realities of data storage, meeting the problems of each era. However, due to the need to take benefit from all the advantages that each type of database offers, the concept of Polyglot Persistence has emerged, which allows the integration of several types of databases in a single system. This approach aims to get the best out of each database, presenting a reliable and alternative solution to systems with only one type of database. As such, this work aims at the analysis of Polyglot Persistence approach to compare systems composed of several database management systems versus those using a single database engine, in order to verify if this approach is useful and advantageous. In this way, a proof of concept was elaborated, based on a proposed problem, with the objective of analyzing two systems, a single and another polyglot, based on three different data volumes. For this, it was necessary to proceed to the analysis and choice of the database management systems to be used and to assemble the test environments, for both systems. Using a number of individual queries (for each database) and global queries (set of databases that make up the polyglot system), the results obtained were analyzed using the performance metric relative to the query times. The work and the results obtained showed an increase in the performance, regarding the individual use of the databases. In spite of a slight increase, the results are not clear and need further investigation. Finally, it is possible to affirm that the polyglot approach is mainly useful in complex systems, where the volume of data is high, and it is intended to store different types of data

Transaction behaviour in large database environments: A methodological approach

This thesis presents the CITY benchmark, a database benchmark that fairly represents On-Line Transaction Processing (OLTP) environments. It analyses the most widely used benchmarks in general putting more emphasis on the Wisconsin benchmark and the Transaction Processing Council (TPC) benchmarks (TPC-A, TPC- B and TPC-C) in particular. It also presents an empirical approach to examine the workload of those benchmarks and discovered several technical limitations in their scripts. The thesis also presents an investigation of on-line transactions in large database environments. The tested environments were three of the largest organisations in the UK, those organisations were different in objectives and activities. The investigation identified on-line transaction behaviour and defined the salient characteristics of databases in high-volume transaction environments. The findings from those studies established the basis of a transaction and set of tables that are representative of them. The CITY benchmark design is directly driven from the findings from the empirical studies. The benchmark design took into consideration all the critiques directed towards the TPC benchmarks A, B and C. It is the first benchmark that is designed as a result of studying the behaviour of on-line transactions and databases in large database environments. The CITY benchmark is mainly designed to test and compare database systems performance in high-volume transaction environments (OLTP). The work revealed the salient characteristics of large database environments and identified a typical behaviour of on-line transaction in OLTP environments. This research has clearly shown that the TPC benchmarks are not representative to the domain of high-volume transactions environments (OLTP) and it explained why they could be misleading if used to test database management systems in this domain. Additionally, this thesis presents a database performance evaluation methodology that is based on in-depth studies in large database environments

A method to evaluate database management systems for Big Data : focus on spatial data

Big data of type spatial is growing exponentially with the highest rate due to extensive growth in usage of sensors, IoT and mobile devices’ spatial data generation, therefore maintaining, processing and using such data efficiently, effectively with high performance has become one of the top priorities for Database management system providers, hence spatial database features and datatypes have become serious criteria in evaluating database management systems that are supposed to work as the back-end for spatial applications and services. With exponential growth of data and introducing of new types of data, “Big Data” has become strongly focused area that has gained the attention of different sectors e.g. academia, industries and governments to other organizations and studies. The rising trend in high resolution and large-scale geographical information systems have resulted in more companies providing location-based applications and services, therefore finding a proper database management system solution that can support spatial big data features, with multi-model big data support that is reliable and affordable has become a business need for many companies. Concerning the fact that choosing proper solution for any software project can be crucial due to the total cost and desired functionalities that any product could possibly bring into the solution. Migration is also a very complicated and costly procedure that many companies should avoid, which justifies the criticality of choosing the right solution based on the specific needs of any organization. Companies providing spatial applications and services are growing with the common concern of providing successful solutions and robust services. One of the most significant elements that ensures services’ and hence the providers’ reputation and positive depiction is services’ high availability. The possible future work for the thesis could be to develop the framework into a decision support solution for IT businesses with emphasize on spatial features. Another possibility for the future works would be to evaluate the framework by testing the evaluation framework on many other different DBMSs