Data Warehouses (DWs) are repositories containing the unified history of an enterprise used by decision makers for performance measurement and decision support. The data must be Extracted from heterogeneous information sources, Transformed and integrated to be Loaded (ETL) into the DW, using ETL tools, which are mainly procedural. This means that the knowledge of the procedures and adopted poli...

ETL (Extract-Transform-Load) systems are formed by processes responsible for the extraction of data from several sources, cleaning and transforming it in accordance with some prerequisites of a data warehouse, and finally loading it in its multidimensional structures. ETL processes are the most complex tasks involved within the development of a Data Warehousing System, being crucial to model th...

ETL tools allow the definition of sometimes complex processes to extract, transform, and load heterogeneous data into a data warehouse or to perform other data migration tasks. In larger organizations many ETL processes of different data integration projects are accumulated. Such processes can encompass common sub-processes, shared data sources and targets, and same or similar operations. Howev...

SAS® Data Integration Studio is a great tool for building and maintaining data warehouses and data marts. The performance of the extract, transform, and load (ETL) job is critical for building data warehouses and data marts. This paper discusses the time-consuming data transformations related to ETL processes in SAS Data Integration Studio. The performance for each data transformation is benchm...

In this paper we investigate the problem of providing scalability to near-real-time ETL+Q (Extract, transform, load and querying) process of data warehouses. In general, data loading, transformation and integration are heavy tasks that are performed only periodically during small fixed time windows. We propose an approach to enable the automatic scalability and freshness of any data warehouse a...

In this paper, we visit the problem of the management of inconsistencies emerging on ETL processes as results of evolution operations occurring at their sources. We abstract Extract-Transform-Load (ETL) activities as queries and sequences of views. ETL activities and its sources are uniformly modeled as a graph that is annotated with rules for the management of evolution events. Given a change ...

We demonstrate a new solution-processed electron transport layer (ETL), zinc oxide doped with cesium carbonate (ZnO:Cs2CO3), for achieving organic photovoltaics (OPVs) with good operational stability at ambient air. An OPV employing the ZnO:Cs2CO3 ETL exhibits a fill factor of 62%, an open circuit voltage of 0.90 V, and a short circuit current density of -6.14 mA/cm(2) along with 3.43% power co...

Near real time ETL deviates from the traditional conception of data warehouse refreshment, which is performed off-line in a batch mode, and adopts the strategy of propagating changes that take place in the sources towards the data warehouse to the extent that both the sources and the warehouse can sustain the incurred workload. In this article, we review the state of the art for both convention...

ELT – extract, load, and transform – is replacing ETL (extract, transform, load) as the usual method of populating data warehouses. Modern data warehouse appliances and appliance-like systems, such as IBM Pure Data / Netezza, are ideally suited for an ELT environment. ELTMaestro is a framework for ELT development, deployment, and production. ELTMaestro is not an ETL tool that has been repurpose...

We present UnifiedViews, an Extract-Transform-Load (ETL) framework that allows users to define, execute, monitor, debug, schedule, and share ETL data processing tasks, which may employ custom plugins (data processing units, DPUs) created by users. UnifiedViews differs from other ETL frameworks by natively supporting RDF data and ontologies. In this paper, we introduce UnifiedViews and discuss f...