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Auflistung nach Autor:in "Dessloch, Stefan"

1 - 6 von 6
  • Zeitschriftenartikel
    A Real-time Materialized View Approach for Analytic Flows in Hybrid Cloud Environments
    (Datenbank-Spektrum: Vol. 14, No. 2, 2014) Qu, Weiping; Dessloch, Stefan
    Next-generation business intelligence (BI) enables enterprises to quickly react in changing business environments. Increasingly, data integration pipelines need to be merged with query pipelines for real-time analytics from operational data. Newly emerging hybrid analytic flows have been becoming attractive which consist of a set of extract-transform-load (ETL) jobs together with analytic jobs running over multiple platforms with different functionality.In traditional databases, materialized views are used to optimize query performance. In cross-platform, large-scale data transformation environments, similar challenges (e.g. view selection) arise when using materialized views. In this work, we propose an approach that generates materialized views in hybrid flows and maintains these views in a query-driven, incremental manner. To accelerate data integration processes, the location of a materialization point in a transformation flow varies dynamically based on metrics like source update rates and maintenance cost in terms of flow operations. Besides, by picking up the most suitable platform for accommodating views, for example, materializing and maintaining intermediate results of Hadoop jobs in relational databases, better performance has been shown.
  • Konferenzbeitrag
    Change Management in Large Information Infrastructures – Representing and Analyzing Arbitrary Metadata
    (Datenbanksysteme in Business, Technologie und Web (BTW 2007) – 12. Fachtagung des GI-Fachbereichs "Datenbanken und Informationssysteme" (DBIS), 2007) Stumm, Boris; Dessloch, Stefan
    With information infrastructures getting more and more complex, it becomes necessary to give automated support for managing the evolution of the infrastructure. If changes are detected in a single system, the potential impact on other systems has to be calculated and appropriate countermeasures have to be initiated to prevent failures and data corruption that span several systems. This is the goal of Caro, our approach to change impact analysis in large information infrastructures. In this paper we present how we model the metadata of information systems to make a global analysis possible, regardless of the data models used, and how the analysis process works.
  • Konferenzbeitrag
    Formalizing ETL jobs for incremental loading of data warehouses
    (Datenbanksysteme in Business, Technologie und Web (BTW) – 13. Fachtagung des GI-Fachbereichs "Datenbanken und Informationssysteme" (DBIS), 2009) Jörg, Thomas; Dessloch, Stefan
    Extract-transform-load (ETL) tools are primarily designed for data warehouse loading, i.e. to perform physical data integration. When the operational data sources happen to change, the data warehouse gets stale. To ensure data timeliness, the data warehou
  • Konferenzbeitrag
    GEM: A generic visualization and editing facility for heterogeneous metadata
    (Datenbanksysteme in Business, Technologie und Web (BTW) – 13. Fachtagung des GI-Fachbereichs "Datenbanken und Informationssysteme" (DBIS), 2009) Göres, Jürgen; Jörg, Thomas; Stumm, Boris; Dessloch, Stefan
    Many model management tasks, e.g., schema matching or merging, require the manual handling of metadata. Given the diversity of metadata, its many different representations and modes of manipulation, meta-modeland task-specific editors usually have to be c
  • Konferenzbeitrag
    Towards an Integrated Model for Data, Metadata, and Operations
    (Datenbanksysteme in Business, Technologie und Web (BTW 2007) – 12. Fachtagung des GI-Fachbereichs "Datenbanken und Informationssysteme" (DBIS), 2007) Göres, Jürgen; Dessloch, Stefan
    Information integration requires manipulating data and metadata in ways that in general go beyond a single existing transformation formalism. As a result, a complete source-to-target mapping can only be expressed by combining different techniques like query languages, wrappers, scripting, etc., which are often specific to a single integration platform or vendor. Such a mapping is not portable across different alternative deployment scenarios, thus limiting the mapping's reusability and putting the considerable investment required to create it at risk. To avoid this vendor lock-in, we define an integrated representation for operations on arbitrary data and metadata that is independent of any specific metamodel or transformation language. Using it, we can express mappings in an abstract, vendor-neutral form, improving the interoperability of integration tools and the flexibility for the deployment of mappings.
  • Konferenzbeitrag
    View maintenance using partial deltas
    (Datenbanksysteme für Business, Technologie und Web (BTW), 2011) Jörg, Thomas; Dessloch, Stefan
    This paper addresses maintenance of materialized views in a warehousing environment, where views reside on a remote database. We analyze so called Change Data Capture techniques used to capture changes (also referred to as deltas) at the source systems. We show that many existing CDC techniques do not provide complete deltas but rather incomplete (or partial) deltas. Traditional view maintenance techniques, however, require complete deltas as input. We propose a generalized technique that allows for maintaining a class of materialized views using partial deltas.