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Auflistung nach Schlagwort "Databases"

1 - 6 von 6
  • Zeitschriftenartikel
    ADAMpro: Database Support for Big Multimedia Retrieval
    (Datenbank-Spektrum: Vol. 16, No. 1, 2016) Giangreco, Ivan; Schuldt, Heiko
    For supporting retrieval tasks within large multimedia collections, not only the sheer size of data but also the complexity of data and their associated metadata pose a challenge. Applications that have to deal with big multimedia collections need to manage the volume of data and to effectively and efficiently search within these data. When providing similarity search, a multimedia retrieval system has to consider the actual multimedia content, the corresponding structured metadata (e.g., content author, creation date, etc.) and—for providing similarity queries—the extracted low-level features stored as densely populated high-dimensional feature vectors. In this paper, we present ADAMpro, a combined database and information retrieval system that is particularly tailored to big multimedia collections. ADAMpro follows a modular architecture for storing structured metadata, as well as the extracted feature vectors and it provides various index structures, i.e., Locality-Sensitive Hashing, Spectral Hashing, and the VA-File, for a fast retrieval in the context of a similarity search. Since similarity queries are often long-running, ADAMpro supports progressive queries that provide the user with streaming result lists by returning (possibly imprecise) results as soon as they become available. We provide the results of an evaluation of ADAMpro on the basis of several collection sizes up to 50 million entries and feature vectors with different numbers of dimensions.
  • Konferenzbeitrag
    Data Analytics as a Service – A Summary of Keynotes and Poster of the DAS Workshop: An Extended Abstracts Point of View
    (INFORMATIK 2024, 2024) Kilias, Torsten; Gao, Raymond
    This paper shows an overview and summary of the practical keynotes and poster of the DAS workshop given by Torsten Kilias and Raymond Gao. Insights into Exasol databases and new possibilities for analytical approaches for requirement refinement are described. The two independent authors present their practical work.
  • Konferenzbeitrag
    A Decision Tree Approach for the Classification of Mistakes of Students Learning SQL, a case study about SELECT statements
    (DELFI 2020 – Die 18. Fachtagung Bildungstechnologien der Gesellschaft für Informatik e.V., 2020) Faeskorn-Woyke, Heide; Bertelsmeier, Birgit; Strohschein, Jan
    TH Köln provides a web-based e-learning platform edb4, where novices can do their first steps in SQL. The goal of this paper is to build a decision tree (manually) that classifies the novice's errors. To do so we logged data containing tasks, solutions, and wrong statements over seven months and got a table with 7533 rows as a training set. Each leaf node of the decision tree is a class of errors of similar type and generates an error message with feedback to help the user to solve the task. Interesting and surprising are the mistakes that SQL novices make. The result improves the first steps of learning SQL in a simple and personalized way and gives the teachers hints to improve their learning outputs.
  • Zeitschriftenartikel
    Designing an Event Store for a Modern Three-layer Storage Hierarchy
    (Datenbank-Spektrum: Vol. 20, No. 3, 2020) Glombiewski, Nikolaus; Götze, Philipp; Körber, Michael; Morgen, Andreas; Seeger, Bernhard
    Event stores face the difficult challenge of continuously ingesting massive temporal data streams while satisfying demanding query and recovery requirements. Many of today’s systems deal with multiple hardware-based trade-offs. For instance, long-term storage solutions balance keeping data in cheap secondary media (SSDs, HDDs) and performance-oriented main-memory caches. As an alternative, in-memory systems focus on performance, while sacrificing monetary costs, and, to some degree, recovery guarantees. The advent of persistent memory (PMem) led to a multitude of novel research proposals aiming to alleviate those trade-offs in various fields. So far, however, there is no proposal for a PMem-powered specialized event store. Based on ChronicleDB, we will present several complementary approaches for a three-layer architecture featuring main memory, PMem, and secondary storage. We enhance some of ChronicleDB’s components with PMem for better insertion and query performance as well as better recovery guarantees. At the same time, the three-layer architecture aims to keep the overall dollar cost of a system low. The limitations and opportunities of a PMem-enhanced event store serve as important groundwork for comprehensive system design exploiting a modern storage hierarchy.
  • Zeitschriftenartikel
    SABIO-RK, von Daten in der Publikation zur Suchlösung für Spezialisten
    (Datenbank-Spektrum: Vol. 17, No. 1, 2017) Müller, Wolfgang; Bittkowski, Meik; Golebiewski, Martin; Kania, Renate; Rey, Maja; Weidemann, Andreas; Wittig, Ulrike
    SABIO-RK ist eine Datenbank, in der Spezialisten aus der Systembiologie Daten aus biochemischen Publikationen suchen, finden, und in geeigneten Formaten extrahieren können. Der Artikel beschreibt, wie Kuratierung durch Experten, standardisierte Struktur, flexible Suche und einfacher Datenexport ineinandergreifen, um den Informationsbedarf der Nutzer zu befriedigen.
  • Zeitschriftenartikel
    SQLValidator – An Online Student Playground to Learn SQL
    (Datenbank-Spektrum: Vol. 21, No. 2, 2021) Obionwu, Victor; Broneske, David; Hawlitschek, Anja; Köppen, Veit; Saake, Gunter
    The Structured Query Language (SQL) is the most widely-used language in database-related courses. As a consequence, writing SQL queries is a fundamental expectation from any university course in database systems. Practical exercises are an essential part of the SQL learning experience. These exercises enable participants to practice and acquire experience in the use of the different SQL concepts, such as clauses, predicates, and expressions. To this end, we developed the tool SQLValidator as a web-based interactive tool for learning and practicing SQL. Apart from using it for teaching, we also use it to administer questionnaires and practice tests to improve students’ learning experience. In this paper, we present the architecture and functions of SQLValidator. In order to assess the usefulness of SQLValidator, we monitor the performance of our students based on the semester activities and examinations. Our evaluation shows that SQLValidator is an effective tool that improves a student’s learning experience when learning SQL.