22,652 research outputs found
On-Demand Big Data Integration: A Hybrid ETL Approach for Reproducible Scientific Research
Scientific research requires access, analysis, and sharing of data that is
distributed across various heterogeneous data sources at the scale of the
Internet. An eager ETL process constructs an integrated data repository as its
first step, integrating and loading data in its entirety from the data sources.
The bootstrapping of this process is not efficient for scientific research that
requires access to data from very large and typically numerous distributed data
sources. a lazy ETL process loads only the metadata, but still eagerly. Lazy
ETL is faster in bootstrapping. However, queries on the integrated data
repository of eager ETL perform faster, due to the availability of the entire
data beforehand.
In this paper, we propose a novel ETL approach for scientific data
integration, as a hybrid of eager and lazy ETL approaches, and applied both to
data as well as metadata. This way, Hybrid ETL supports incremental integration
and loading of metadata and data from the data sources. We incorporate a
human-in-the-loop approach, to enhance the hybrid ETL, with selective data
integration driven by the user queries and sharing of integrated data between
users. We implement our hybrid ETL approach in a prototype platform, Obidos,
and evaluate it in the context of data sharing for medical research. Obidos
outperforms both the eager ETL and lazy ETL approaches, for scientific research
data integration and sharing, through its selective loading of data and
metadata, while storing the integrated data in a scalable integrated data
repository.Comment: Pre-print Submitted to the DMAH Special Issue of the Springer DAPD
Journa
Ringo: Interactive Graph Analytics on Big-Memory Machines
We present Ringo, a system for analysis of large graphs. Graphs provide a way
to represent and analyze systems of interacting objects (people, proteins,
webpages) with edges between the objects denoting interactions (friendships,
physical interactions, links). Mining graphs provides valuable insights about
individual objects as well as the relationships among them.
In building Ringo, we take advantage of the fact that machines with large
memory and many cores are widely available and also relatively affordable. This
allows us to build an easy-to-use interactive high-performance graph analytics
system. Graphs also need to be built from input data, which often resides in
the form of relational tables. Thus, Ringo provides rich functionality for
manipulating raw input data tables into various kinds of graphs. Furthermore,
Ringo also provides over 200 graph analytics functions that can then be applied
to constructed graphs.
We show that a single big-memory machine provides a very attractive platform
for performing analytics on all but the largest graphs as it offers excellent
performance and ease of use as compared to alternative approaches. With Ringo,
we also demonstrate how to integrate graph analytics with an iterative process
of trial-and-error data exploration and rapid experimentation, common in data
mining workloads.Comment: 6 pages, 2 figure
EAGLE—A Scalable Query Processing Engine for Linked Sensor Data
Recently, many approaches have been proposed to manage sensor data using semantic web technologies for effective heterogeneous data integration. However, our empirical observations revealed that these solutions primarily focused on semantic relationships and unfortunately paid less attention to spatio–temporal correlations. Most semantic approaches do not have spatio–temporal support. Some of them have attempted to provide full spatio–temporal support, but have poor performance for complex spatio–temporal aggregate queries. In addition, while the volume of sensor data is rapidly growing, the challenge of querying and managing the massive volumes of data generated by sensing devices still remains unsolved. In this article, we introduce EAGLE, a spatio–temporal query engine for querying sensor data based on the linked data model. The ultimate goal of EAGLE is to provide an elastic and scalable system which allows fast searching and analysis with respect to the relationships of space, time and semantics in sensor data. We also extend SPARQL with a set of new query operators in order to support spatio–temporal computing in the linked sensor data context.EC/H2020/732679/EU/ACTivating InnoVative IoT smart living environments for AGEing well/ACTIVAGEEC/H2020/661180/EU/A Scalable and Elastic Platform for Near-Realtime Analytics for The Graph of Everything/SMARTE
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