Control Infrastructure for a Pulsed Ion Accelerator

We report on updates to the accelerator controls for the Neutralized Drift Compression Experiment II, a pulsed induction-type accelerator for heavy ions. The control infrastructure is built around a LabVIEW interface combined with an Apache Cassandra backend for data archiving. Recent upgrades added the storing and retrieving of device settings into the database, as well as ZeroMQ as a message broker that replaces LabVIEW's shared variables. Converting to ZeroMQ also allows easy access via other programming languages, such as Python

Survey of time series database technology

This report has been prepared by Epimorphics Ltd. as part of the ENTRAIN project (NERC grant number NE/S016244/1) which is a feasibility project within the “NERC Constructing a Digital Environment Strategic Priorities Fund Programme”. The Centre for Ecology and Hydrology(CEH) is a research organisation focusing on land and freshwater ecosystems and their interaction with the atmosphere. The organization manages a number of sensor networks to monitor the environment, and also handles large databases of 3rd party data (e.g. river flows measured by the Environment Agency and equivalents in Scotland and Wales). Data from these networks is stored and made available to users, both internally (through direct query of databases, and externally via web-services). The ENTRAIN project aims to address a number of issues in relation to sensor data storage and integration, using a number of hydrological datasets to help define use cases: COSMOS-UK (a network of ~50 sites measuring soil moisture and meteorological variables at 1-30 minute resolutions); the CEH Greenhouse Gas (GHG) network (~15 sites measuring sub-second fluxes of gases and moisture, subsequently processed up to 30-minute aggregations); the Thames Initiative (a database of weekly and hourly water quality samples from sites around the Thames basin). In addition this report considers the UK National River Flow Archive, a database of daily river flows and catchment rainfall derived by regional environmental agencies from 15-minute measurements of river levels and flows. CEH commissioned this report to survey alternative technologies for storing sensor data that scale better, could manage larger data volumes more easily and less expensively, and that might be readily deployed on different infrastructures

NoSQL Databases as Social Networks Storage Systems

The paper presents analysis of the storage systems used by social network sites. Namely, the social networks are one of the main driving forces behind the NoSQL database development. Facebook and Twitter were, together with other the Big Data players like Google and Amazon, first faced with the limitations of relational databases in solving their needs related to unprecedented transaction volumes, expectations of low-latency access to massive datasets, and nearly perfect service availability while operating in an unreliable environment. The first NoSQL databases arose as internal solutions created out of necessity, and not with the intention to abandon relational databases. But the main question is if, after more than ten years of development, NoSQL databases proved that they could be valuable storage solutions for social networks’ data. The paper shows that there is still a lot of room for improvement in the use of NoSQL in social networks and provides some suggestions on how NoSQL databases can bring additional value to social network sites. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

NORA: Scalable OWL reasoner based on NoSQL databasesand Apache Spark

Reasoning is the process of inferring new knowledge and identifying inconsis-tencies within ontologies. Traditional techniques often prove inadequate whenreasoning over large Knowledge Bases containing millions or billions of facts.This article introduces NORA, a persistent and scalable OWL reasoner built ontop of Apache Spark, designed to address the challenges of reasoning over exten-sive and complex ontologies. NORA exploits the scalability of NoSQL databasesto effectively apply inference rules to Big Data ontologies with large ABoxes. Tofacilitatescalablereasoning,OWLdata,includingclassandpropertyhierarchiesand instances, are materialized in the Apache Cassandra database. Spark pro-grams are then evaluated iteratively, uncovering new implicit knowledge fromthe dataset and leading to enhanced performance and more efficient reasoningover large-scale ontologies. NORA has undergone a thorough evaluation withdifferent benchmarking ontologies of varying sizes to assess the scalability of thedeveloped solution.Funding for open access charge: Universidad de Málaga / CBUA This work has been partially funded by grant (funded by MCIN/AEI/10.13039/501100011033/) PID2020-112540RB-C41,AETHER-UMA (A smart data holistic approach for context-aware data analytics: semantics and context exploita-tion). Antonio Benítez-Hidalgo is supported by Grant PRE2018-084280 (Spanish Ministry of Science, Innovation andUniversities)

Data Integration over NoSQL Stores Using Access Path Based Mappings

International audienceDue to the large amount of data generated by user interactions on the Web, some companies are currently innovating in the domain of data management by designing their own systems. Many of them are referred to as NoSQL databases, standing for 'Not only SQL'. With their wide adoption will emerge new needs and data integration will certainly be one of them. In this paper, we adapt a framework encountered for the integration of relational data to a broader context where both NoSQL and relational databases can be integrated. One important extension consists in the efficient answering of queries expressed over these data sources. The highly denormalized aspect of NoSQL databases results in varying performance costs for several possible query translations. Thus a data integration targeting NoSQL databases needs to generate an optimized translation for a given query. Our contributions are to propose (i) an access path based mapping solution that takes benefit of the design choices of each data source, (ii) integrate preferences to handle conflicts between sources and (iii) a query language that bridges the gap between the SQL query expressed by the user and the query language of the data sources. We also present a prototype implementation, where the target schema is represented as a set of relations and which enables the integration of two of the most popular NoSQL database models, namely document and a column family stores

Benchmarking Big Data OLAP NoSQL Databases

With the advent of Big Data, new challenges have emerged regarding the evaluation of decision support systems (DSS). Existing evaluation benchmarks are not configured to handle a massive data volume and wide data diversity. In this paper, we introduce a new DSS benchmark that supports multiple data storage systems, such as relational and Not Only SQL (NoSQL) systems. Our scheme recognizes numerous data models (snowflake, star and flat topologies) and several data formats (CSV, JSON, TBL, XML, etc.). It entails complex data generation characterized within “volume, variety, and velocity” framework (3 V). Next, our scheme enables distributed and parallel data generation. Furthermore, we exhibit some experimental results with KoalaBench