Now showing items 1-20 of 98

  • A cost-based storage format selector for materialized results in big data frameworks 

    Munir, Rana Faisal; Abelló Gamazo, Alberto; Romero Moral, Óscar; Thiele, Maik; Lehner, Wolfgang (2019-05-08)
    Article
    Restricted access - publisher's policy
    Modern big data frameworks (such as Hadoop and Spark) allow multiple users to do large-scale analysis simultaneously, by deploying data-intensive workflows (DIWs). These DIWs of different users share many common tasks (i.e, ...
  • Adaptació d'assignatures de bases de dades a l'EEES 

    Martín Escofet, Carme; Abelló Gamazo, Alberto; Burgués Illa, Xavier; Casany Guerrero, María José; Quer, Carme; Rodríguez González, María Elena; Urpí Tubella, Antoni (2010)
    Conference report
    Open Access
    Els canvis recents en els plans d'estudis de la UPC i la UOC tenen en compte el nou espai europeu d'educació superior (EEES). Una de les conseqüències directes d'aquests canvis és la necessitat d'afitar i optimitzar el ...
  • Adapting LEARN-SQL to database computer supported cooperative learning 

    Burgués Illa, Xavier; Martín Escofet, Carme; Quer, Carme; Abelló Gamazo, Alberto; Casany Guerrero, María José; Urpí Tubella, Antoni; Rodríguez González, María Elena (2010)
    Conference report
    Open Access
    LEARN-SQL is a tool that we are using since three years ago in several database courses, and that has shown its positive effects in the learning of different database issues. This tool allows proposing remote questionnaires ...
  • A Data-driven approach to improve the process of data-intensive API creation and evolution 

    Abelló Gamazo, Alberto; Ayala Martínez, Claudia Patricia; Farré Tost, Carles; Gómez Seoane, Cristina; Oriol Hilari, Marc; Romero Moral, Óscar (CEUR-WS.org, 2017)
    Conference report
    Open Access
    The market of data-intensive Application Programming Interfaces (APIs) has recently experienced an exponential growth, but the creation and evolution of such APIs is still done ad-hoc, with little automated support and ...
  • A framework for multidimensional design of data warehouses from ontologies 

    Romero Moral, Óscar; Abelló Gamazo, Alberto (2009-07)
    External research report
    Open Access
    Some research efforts have proposed the automation of the data warehouse design in order to free this task of being (completely) performed by an expert and facilitate the whole process. Most advanced approaches exclusively ...
  • A framework for user-centered declarative ETL 

    Theodorou, Vasileios; Abelló Gamazo, Alberto; Thiele, Maik; Lehner, Wolfgang (2014)
    Conference report
    Open Access
    As business requirements evolve with increasing information density and velocity, there is a growing need for efficiency and automation of Extract-Transform-Load (ETL) processes. Current approaches for the modeling and ...
  • Aggregating energy flexibilities under constraints 

    Valsomatzis, Emmanouil; Bach Pedersen, Torben; Abelló Gamazo, Alberto; Hose, Katja (Institute of Electrical and Electronics Engineers (IEEE), 2016)
    Conference report
    Open Access
    The flexibility of individual energy prosumers (producers and/or consumers) has drawn a lot of attention in recent years. Aggregation of such flexibilities provides prosumers with the opportunity to directly participate ...
  • An integration-oriented ontology to govern evolution in big data ecosystems 

    Nadal Francesch, Sergi; Romero Moral, Óscar; Abelló Gamazo, Alberto; Vassiliadis, Panos; Vansummeren, Stijn (2019-01)
    Article
    Restricted access - publisher's policy
    Big Data architectures allow to flexibly store and process heterogeneous data, from multiple sources, in their original format. The structure of those data, commonly supplied by means of REST APIs, is continuously evolving. ...
  • An integration-oriented ontology to govern evolution in big data ecosystems 

    Nadal Francesch, Sergi; Romero Moral, Óscar; Abelló Gamazo, Alberto; Vassiliadis, Panos; Vansummeren, Stijn (CEUR-WS.org, 2017)
    Conference lecture
    Open Access
    Big Data architectures allow to flexibly store and process heterogeneous data, from multiple sources, in its original format. The structure of those data, commonly supplied by means of REST APIs, is continuously evolving, ...
  • Approximating the DTD of a set of XML documents 

    Abelló Gamazo, Alberto; Palol Arregui, Xavier de; Hacid, Mohand-Saïd (2005-03)
    External research report
    Open Access
    The WWW contains a huge amount of documents. Some of them share the subject, but are generated by different people or even organizations. To guarantee the interchange of such documents, we can use XML. This allows to share ...
  • Approximating the schema of a set of documents by means of resemblance 

    Abelló Gamazo, Alberto; Palol, Xavier de; Hacid, Mohand-Saïd (Springer, 2018-06-02)
    Article
    Open Access
    The WWW contains a huge amount of documents. Some of them share the same subject, but are generated by different people or even by different organizations. A semi-structured model allows to share documents that do not have ...
  • A requirement-driven approach to the design and evolution of data warehouses 

    Jovanovic, Petar; Romero Moral, Óscar; Simitsis, Alkis; Abelló Gamazo, Alberto; Mayorova, Daria (2014-08-01)
    Article
    Restricted access - publisher's policy
    Designing data warehouse (DW) systems in highly dynamic enterprise environments is not an easy task. At each moment, the multidimensional (MD) schema needs to satisfy the set of information requirements posed by the business ...
  • A situational approach for the definition and tailoring of a data-driven software evolution method 

    Franch Gutiérrez, Javier; Ralyté, Jolita; Perini, Anna; Abelló Gamazo, Alberto; Ameller, David; Gorroñogoitia, Jesús; Nadal Francesch, Sergi; Oriol Hilari, Marc; Seyff, Norbert; Siena, Alberto; Susi, Angelo (Springer, 2018)
    Conference report
    Open Access
    Successful software evolution heavily depends on the selection of the right features to be included in the next release. Such selection is difficult, and companies often report bad experiences about user acceptance. To ...
  • A software reference architecture for semantic-aware big data systems 

    Nadal Francesch, Sergi; Herrero Otal, Víctor; Romero Moral, Óscar; Abelló Gamazo, Alberto; Franch Gutiérrez, Javier; Vansummeren, Stijn; Valerio, Danilo (2016-06-13)
    Article
    Open Access
    Context: Big Data systems are a class of software systems that ingest, store, process and serve massive amounts of heterogeneous data, from multiple sources. Despite their undisputed impact in current society, their ...
  • A software tool for e-assessment of relational database skills 

    Abelló Gamazo, Alberto; Burgués Illa, Xavier; Casany Guerrero, María José; Martín Escofet, Carme; Quer, Carme; Rodríguez González, M. Elena; Romero Moral, Óscar; Urpí Tubella, Antoni (Tempus Publications, 2016-01-01)
    Article
    Restricted access - publisher's policy
    The objective of this paper is to present a software tool for the e-assessment of relational database skills. The tool is referred to as LearnSQL (Learning Environment for Automatic Rating of Notions of SQL). LearnSQL is ...
  • ATUN-HL: auto tuning of hybrid layouts using workload and data characteristics 

    Munir, Rana Faisal; Abelló Gamazo, Alberto; Romero Moral, Óscar; Thiele, Maik; Lehner, Wolfgang (2018)
    Conference report
    Open Access
    Ad-hoc analysis implies processing data in near real-time. Thus, raw data (i.e., neither normalized nor transformed) is typically dumped into a distributed engine, where it is generally stored into a hybrid layout. Hybrid ...
  • A unified view of data-intensive flows in business intelligence systems : a survey 

    Jovanovic, Petar; Romero Moral, Óscar; Abelló Gamazo, Alberto (2016-12)
    Article
    Open Access
    Data-intensive flows are central processes in today’s business intelligence (BI) systems, deploying different technologies to deliver data, from a multitude of data sources, in user-preferred and analysis-ready formats. ...
  • Automated data pre-processing via meta-learning 

    Bilalli, Besim; Abelló Gamazo, Alberto; Aluja Banet, Tomàs; Wrembel, Robert (2016)
    Conference report
    Open Access
    A data mining algorithm may perform differently on datasets with different characteristics, e.g., it might perform better on a dataset with continuous attributes rather than with categorical attributes, or the other way ...
  • Automatic multidimensional design of data warehouses from requirements 

    Romero Moral, Óscar; Abelló Gamazo, Alberto (2009-07)
    External research report
    Open Access
    The ideal scenario to derive the multidimensional conceptual schema of a data warehouse would entail a hybrid approach (i.e. a combined data-driven and requirement-driven approach). Thus, the resulting multidimensional ...
  • Avaluació de la incorporació d'activitats d'aprenentatge actiu i cooperatiu a les assignatures de bases de dades de la Facultat d'Informàtica de Barcelona. 

    Martín Escofet, Carme; Urpí Tubella, Antoni; Abelló Gamazo, Alberto; Burgués Illa, Xavier; Casany Guerrero, María José; Quer, Carme; Rodríguez González, María Elena (2012)
    Conference report
    Open Access
    Una de les idees principals del canvi al nou Espai Europeu d'Educació Superior és que les assignatures no es redueixin simplement a un conjunt de classes magistrals, sinó que les classes incorporin activitats d'aprenentatge ...