scholarly journals Cost Models for Selecting Materialized Views in Public Clouds

2014 ◽  
Vol 10 (4) ◽  
pp. 1-25 ◽  
Author(s):  
Romain Perriot ◽  
Jérémy Pfeifer ◽  
Laurent d'Orazio ◽  
Bruno Bachelet ◽  
Sandro Bimonte ◽  
...  
Keyword(s):  
Response Time ◽  
Data Structures ◽  
Performance Optimization ◽  
Optimization Problem ◽  
Materialized Views ◽  
Cost Models ◽  
Public Cloud ◽  
Total Response ◽  
Query Response Time ◽  
Total Response Time

Data warehouse performance is usually achieved through physical data structures such as indexes or materialized views. In this context, cost models can help select a relevant set of such performance optimization structures. Nevertheless, selection becomes more complex in the cloud. The criterion to optimize is indeed at least two-dimensional, with monetary cost balancing overall query response time. This paper introduces new cost models that fit into the pay-as-you-go paradigm of cloud computing. Based on these cost models, an optimization problem is defined to discover, among candidate views, those to be materialized to minimize both the overall cost of using and maintaining the database in a public cloud and the total response time of a given query workload. It experimentally shows that maintaining materialized views is always advantageous, both in terms of performance and cost.

scholarly journals Index and Materialized View Selection in Data Warehouses

2009 ◽  
pp. 693-700 ◽  
Author(s):  
Kamel Aouiche ◽  
Jérôme Darmont
Keyword(s):  
Response Time ◽  
Performance Optimization ◽  
Data Access ◽  
Original Data ◽  
Optimization Techniques ◽  
Access Time ◽  
Materialized Views ◽  
Storage Space ◽  
Data Warehouses ◽  
Query Response Time

Database management systems (DBMSs) require an administrator whose principal tasks are data management, both at the logical and physical levels, as well as performance optimization. With the wide development of databases and data warehouses, minimizing the administration function is crucial. This function includes the selection of suitable physical structures to improve system performance. View materialization and indexing are presumably some of the most effective optimization techniques adopted in relational implementations of data warehouses. Materialized views are physical structures that improve data access time by precomputing intermediary results. Therefore, end-user queries can be efficiently processed through data stored in views and do not need to access the original data. Indexes are also physical structures that allow direct data access. They avoid sequential scans and thereby reduce query response time. Nevertheless, these solutions require additional storage space and entail maintenance overhead. The issue is then to select an appropriate configuration of materialized views and indexes that minimizes both query response time and maintenance cost given a limited storage space. This problem is NP hard (Gupta & Mumick, 2005).

scholarly journals Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in Taekwondo

2012 ◽  
Vol 31 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Isaac Estevan ◽  
Coral Falco ◽  
Octavio Álvarez ◽  
Javier Molina-García
Keyword(s):  
Response Time ◽  
Impact Force ◽  
Large Impact ◽  
Relative Impact ◽  
Total Response ◽  
Male Athletes ◽  
Weight Category ◽  
Total Response Time

Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in TaekwondoIn taekwondo, kick performance is generally measured using impact force and time. This study aimed to analyse performance in the roundhouse kick to the head according to execution distance between and within Olympic weight categories. The participants were 36 male athletes divided into three categories: featherweight (n = 10), welterweight (n = 15) and heavyweight (n = 11). Our results show that taekwondo athletes in all weight categories generate a similar relative impact force. However, the results indicate that weight has a large impact on kick performance, particularly in relation to total response time.

scholarly journals An M/G/l queueing system with fixed feedback policy

2002 ◽  
Vol 44 (2) ◽  
pp. 283-297 ◽  
Author(s):  
Bong Dae Choi ◽  
Bara Kim
Keyword(s):  
Response Time ◽  
Generating Function ◽  
Queueing System ◽  
Probability Generating Function ◽  
Joint Probability ◽  
Fixed Number ◽  
Single Server ◽  
Total Response ◽  
Stieltjes Transform ◽  
Total Response Time

We consider a single server queueing system where each customer visits the queue a fixed number of times before departure. A customer on his j th visit to the queue is defined to be a class-j -customer. We obtain the joint probability generating function for the number of class-j-customers and also obtain the Laplace-Stieltjes transform for the total response time of a customer.

scholarly journals Serviço de atendimento móvel de urgência do Rio Grande do Sul

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Magda Regina Dorr ◽  
Gabriella Barbosa Nadas ◽  
Celia Sapin Duarte ◽  
Cristiane Damiani Tomasi ◽  
Lisiane Tuon
Keyword(s):  
Response Time ◽  
Rural Areas ◽  
Rio Grande ◽  
User Profile ◽  
State Regulation ◽  
Rio Grande Do Sul ◽  
Total Response ◽  
Health Services Administration ◽  
Total Response Time ◽  
Day Of The Week

Objetivo: analisar os atendimentos realizados na Central de Regulação de Urgência/SAMU do Estado do Rio Grande do Sul no período de 2016 e 2017. Metodologia: estudo observacional, descritivo e retrospectivo com abordagem quantitativa. Foram coletados os dados sobre perfil do usuário, dia da semana, classificação de risco, tipo do agravo, tempo médio de atendimento às solicitações, quantitativo de desistência da solicitação e número de chamados não regulados por falta de equipes ou veículos. Resultados: o número de solicitações por motivos clínicos foi 53.8%, destes 51,6% foram média gravidade. A prevalência foi do sexo masculino e idade entre 18 e 29 anos. Em 84,7% dos chamados solicitou-se suporte básico. O tempo resposta total foi entre 30 minutos e 1 hora, maior que o recomendado de acordo com a média nacional, seja nas as zonas urbanas ou rurais. Conclusão: este serviço necessita reduzir o tempo resposta de atendimento das solicitações.Palavras-chave: SAMU; Indicadores; Central de Regulação Estadual; Serviços Médicos de Emergência; Administração de Serviços de Saúde. Objective: to analyze the attendances performed at the Emergency Regulation Center / SAMU of the State of Rio Grande do Sul in 2016 and 2017, focusing in response time. Methodology: observational, descriptive and retrospective study with quantitative approach. Data were collected on user profile, day of the week, risk classification, type of grievance, average time to respond to requests, amount of withdrawal and number of calls not regulated due to lack of teams or vehicles. Results: The number of requests for clinical reasons was 53.8%, of these 51.6% were medium severity. The prevalence was male and aged between 18 and 29 years. In 84.7% of the calls, basic support was requested. The total response time was between 30 minutes and 1 hour, longer than recommended according to the national average, whether in urban or rural areas. Conclusion: After analyzing the calls, it is clear that the worst problem with the calls is the response time, and it is necessary to decrease the same of the requests.Key-words: SAMU; Indicators; Central of State Regulation; Emergency Medical Services; Health Services Administration.   Objetivo: analizar las asistencias realizadas en el Centro de Regulación de Emergencias / SAMU del Estado de Rio Grande do Sul en 2016 y 2017, centrándose en el tiempo de respuesta. Metodología: estudio observacional, descriptivo y retrospectivo con enfoque cuantitativo. Se recopilaron datos sobre el perfil del usuario, el día de la semana, la clasificación de riesgos, el tipo de queja, el tiempo promedio para responder a las solicitudes, la cantidad de retiros y la cantidad de llamadas no reguladas debido a la falta de equipos o vehículos. Resultados: El número de solicitudes por razones clínicas fue del 53.8%, de estas 51.6% fueron de gravedad media. La prevalencia fue masculina y de edades comprendidas entre 18 y 29 años. En el 84.7% de las llamadas, se solicitó soporte básico. El tiempo de respuesta total fue de entre 30 minutos y 1 hora, más de lo recomendado según el promedio nacional, ya sea en áreas urbanas o rurales. Conclusión: Después de analizar las llamadas, está claro que el peor problema con las llamadas es el tiempo de respuesta, y es necesario disminuir las mismas solicitudes.Palabras clave: SAMU; Indicadores; Central de Regulación Estatal; Servicios Médicos de Urgencia; Administración de los Servicios de Salud. 

Efficient Mining of Skyrank Items in Recommender Systems

2012 ◽  
Vol 472-475 ◽  
pp. 3450-3454
Author(s):  
Zhen Hua Huang ◽  
Dong Wang ◽  
Sheng Li Sun
Keyword(s):  
Response Time ◽  
Recommender Systems ◽  
Recommender System ◽  
Efficient Algorithm ◽  
Total Response ◽  
Total Response Time ◽  
Theoretical Analyses

Mining of skyrank items has recently received a lot of attention in recommender system community. Literature [3] presents an efficient algorithm ZHYX to produce the skyrank items in one single subspace. However, in multi-user environments, recommender systems generally receive multiple subspace skyrank queries simultaneously. Hence, in this paper, we propose the first efficient sound and complete algorithm, i.e. AMMSSI(Algorithm for Mining Multiple Subsapce Skyrank Items), to markedly reduce the total response time. The detailed theoretical analyses and extensive experiments demonstrate that our proposed algorithm is both efficient and effective.

scholarly journals Dependence of the integral characteristics of a nematic light modulator on the physical parameters of a liquid crystal

2021 ◽  
Vol 2056 (1) ◽  
pp. 012027
Author(s):  
G V Simonenko
Keyword(s):  
Boundary Conditions ◽  
Response Time ◽  
Twist Angle ◽  
Contrast Ratio ◽  
Dielectric Anisotropy ◽  
Physical Parameters ◽  
High Contrast ◽  
Total Response ◽  
Total Response Time ◽  
Integral Characteristics

Abstract In the present work, the effect of physical constants of an LC material on the integral characteristics of a modulator operating in a waveguide mode in an LC structure with a twist angle of 270 and antisymmetric boundary conditions in the working cell was studied using the method of computer simulation. It is shown that, under antisymmetric boundary conditions, the small value of the total response time of the LC modulator is due to the absence of a “backflow” in the LC cell and the role of only half of the LC working gap thickness in the dynamics of switching between two states in such a device. In addition, it was found that in order to simultaneously achieve high contrast ratios and a short total response time of the device, it is necessary to choose an LC material with a high value of its dielectric anisotropy. In this case, there is an optimal set of elasticity constants for the LC material, which simultaneously realizes a high contrast ratio and a short total response time of the modulator.

scholarly journals MATERIALIZED VIEWS QUANTUM OPTIMIZED PICKING for INDEPENDENT DATA MARTS QUALITY

2020 ◽  
Vol 3 (1) ◽  
pp. 26-39
Author(s):  
Refed Adnan ◽  
Talib M. J. Abbas
Keyword(s):  
Response Time ◽  
Data Warehouse ◽  
Maintenance Cost ◽  
Materialized Views ◽  
Stochastic Algorithm ◽  
Independent Data ◽  
Materialized View ◽  
Query Response Time ◽  
Data Marts ◽  
Better Than

Particular and timely unified information along with quick and effective query response times is the basic fundamental requirement for the success of any collection of independent data marts (data warehouse) which forms Fact Constellation Schema or Galaxy Schema. Because of the materialized view storage area, the materialization of all views is practically impossible thus suitable materialized views (MVs) picking is one of the intelligent decisions in designing a Fact Constellation Schema to get optimal efficiency. This study presents a framework for picking best-materialized view using Quantum Particle Swarm Optimization (QPSO) algorithm where it is one of the stochastic algorithm in order to achieve the effective combination of good query response time, low query handling cost and low view maintenance cost. The results reveals that the proposed method for picking best-materialized view using QPSO algorithm is better than other techniques via computing the ratio of query response time and compare it to the response time of the same queries on the materialized views. Ratio of implementing the query on the base table takes five times more time than the query implementation on the materialized views. Where the response time of queries through MVs access were found 0.084 seconds while by direct access queries were found 0.422 seconds. This outlines that the performance of query through materialized views access is 402.38% better than those directly access via data warehouse-logical.

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