24 documents found, page 1 of 3

MRVs: enforcing numeric invariants in parallel updates to hotspots with randomi...

Performance of transactional systems is degraded by update hotspots as conflicts lead to waiting and wasted work. This is particularly challenging in emerging large-scale database systems, as latency increases the probability of conflicts, state-of-the-art lock-based mitigations are not available, and most alternatives provide only weak consistency and cannot enforce lower bound invariants. We address this chal...

TiQuE: improving the transactional performance of analytical systems for true h...

Transactions have been a key issue in database management for a long time and there are a plethora of architectures and algorithms to support and implement them. The current state-of-the-art is focused on storage management and is tightly coupled with its design, leading, for instance, to the need for completely new engines to support new features such as Hybrid Transactional Analytical Processing (HTAP). We ad...

A utilização de dispositivos wearable e o seu potencial para o diagnóstico da s...

Introdução - A apneia do sono é um distúrbio grave, muito frequente, caracterizado por episódios repetidos de respiração interrompida durante o sono. Estes episódios podem ter uma duração de alguns segundos a vários minutos e ocorrem devido à oclusão dinâmica e repetitiva da faringe. A apneia obstrutiva do sono é a mais grave situação de um espetro de distúrbios obstrutivos das vias aéreas que prejudicam o sono...

Bird taxonomic and functional diversity, group- and species-level effects on a ...

The relative contribution of bird communities to insect pest control has been seldom estimated using trait-based functional diversity indices, in opposition to the general usage of taxonomic indices simply based on the presence and abundance of species. Moreover, few studies attempted to quantify the explicit contribution of functional groups or species of birds to the control of insect pests. We investigated e...

AIDA-DB: a data management architecture for the edge and cloud continuum

There is an increasing demand for stateful edge computing for both complex Virtual Network Functions (VNFs) and application services in emerging 5G networks. Managing a mutable persistent state in the edge does however bring new architectural, performance, and dependability challenges. Not only it has to be integrated with existing cloud-based systems, but also cope with both operational and analytical workload...

Adaptive database synchronization for an online analytical cloud-to-edge continuum

Wide availability of edge computing platforms, as expected in emerging 5G networks, enables a computing continuum between centralized cloud services and the edge of the network, close to end-user devices. This is particularly appealing for online analytics as data collected by devices is made available for decision-making. However, cloud-based parallel-distributed data processing platforms are not able to direc...

Análise da tecno-tipologia da indústria de pedra lascada da anta dos Mosteiros,...

Durante todo o seu percurso académico, foi sempre valorizada a área onde cresceu e viveu um dos autores (NF), realizando trabalhos académicos sobre os vários períodos arqueológicos e os vestígios que o concelho de Castelo de Vide possui. Neste trajecto surge este artigo que tem como objetivo re-analisar o vasto conjunto de pedra lascada da Anta dos Mosteiros, não esquecendo os estudos já realizados, utilizando ...

Local and landscape effects on the Eucalyptus weevil

Totally-ordered prefix parallel snapshot isolation

Distributed data management systems have increasingly been using variants of Snapshot Isolation (SI) as their transactional isolation criteria as it combines strong ACID guarantees with non-blocking reads and scalability. However, most existing proposals are limited by the performance of update propagation and stability detection, in particular, when execution and storage are disaggregated. In this paper, we pr...

Towards generic fine-grained transaction isolation in polystores

Transactional isolation is a challenge for polystores, as along with the limited capabilities of each datastore, we have to contend with their sheer diversity. However, transactional isolation is increasingly desirable as a variety of datastores are being sought after for roles that go beyond data lakes. Transactional guarantees are also relevant for reliability at scale. In this paper, we propose that transact...