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277 results on '"Simitsis, Alkis"'

1. Adversarial Learning in Real-World Fraud Detection: Challenges and Perspectives

Author

Lunghi, Danele, Simitsis, Alkis, Caelen, Olivier, and Bontempi, Gianluca

Subjects
Computer Science - Machine Learning, Computer Science - Cryptography and Security
Abstract

Data economy relies on data-driven systems and complex machine learning applications are fueled by them. Unfortunately, however, machine learning models are exposed to fraudulent activities and adversarial attacks, which threaten their security and trustworthiness. In the last decade or so, the research interest on adversarial machine learning has grown significantly, revealing how learning applications could be severely impacted by effective attacks. Although early results of adversarial machine learning indicate the huge potential of the approach to specific domains such as image processing, still there is a gap in both the research literature and practice regarding how to generalize adversarial techniques in other domains and applications. Fraud detection is a critical defense mechanism for data economy, as it is for other applications as well, which poses several challenges for machine learning. In this work, we describe how attacks against fraud detection systems differ from other applications of adversarial machine learning, and propose a number of interesting directions to bridge this gap.

Published
2023
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2. The Many Faces of Data-centric Workflow Optimization: A Survey

Author

Kougka, Georgia, Gounaris, Anastasios, and Simitsis, Alkis

Subjects
Computer Science - Databases
Abstract

Workflow technology is rapidly evolving and, rather than being limited to modeling the control flow in business processes, is becoming a key mechanism to perform advanced data management, such as big data analytics. This survey focuses on data-centric workflows (or workflows for data analytics or data flows), where a key aspect is data passing through and getting manipulated by a sequence of steps. The large volume and variety of data, the complexity of operations performed, and the long time such workflows take to compute give rise to the need for optimization. In general, data-centric workflow optimization is a technology in evolution. This survey focuses on techniques applicable to workflows comprising arbitrary types of data manipulation steps and semantic inter-dependencies between such steps. Further, it serves a twofold purpose. Firstly, to present the main dimensions of the relevant optimization problems and the types of optimizations that occur before flow execution. Secondly, to provide a concise overview of the existing approaches with a view to highlighting key observations and areas deserving more attention from the community., Comment: 21 pages, 8 figures

Published
2017

4. DBMSs Should Talk Back Too

Author

Simitsis, Alkis and Ioannidis, Yannis

Subjects
Computer Science - Databases, Computer Science - Human-Computer Interaction
Abstract

Natural language user interfaces to database systems have been studied for several decades now. They have mainly focused on parsing and interpreting natural language queries to generate them in a formal database language. We envision the reverse functionality, where the system would be able to take the internal result of that translation, say in SQL form, translate it back into natural language, and show it to the initiator of the query for verification. Likewise, information extraction has received considerable attention in the past ten years or so, identifying structured information in free text so that it may then be stored appropriately and queried. Validation of the records stored with a backward translation into text would again be very powerful. Verification and validation of query and data input of a database system correspond to just one example of the many important applications that would benefit greatly from having mature techniques for translating such database constructs into free-flowing text. The problem appears to be deceivingly simple, as there are no ambiguities or other complications in interpreting internal database elements, so initially a straightforward translation appears adequate. Reality teaches us quite the opposite, however, as the resulting text should be expressive, i.e., accurate in capturing the underlying queries or data, and effective, i.e., allowing fast and unique interpretation of them. Achieving both of these qualities is very difficult and raises several technical challenges that need to be addressed. In this paper, we first expose the reader to several situations and applications that need translation into natural language, thereby, motivating the problem. We then outline, by example, the research problems that need to be solved, separately for data translations and query translations., Comment: CIDR 2009

Published
2009

8. DBPubs

Author

Baid, Akanksha, Balmin, Andrey, Hwang, Heasoo, Nijkamp, Erik, Rao, Jun, Reinwald, Berthold, Simitsis, Alkis, Sismanis, Yannis, and van Ham, Frank

Abstract

DBPubs is a system for effectively analyzing and exploring the content of database publications by combining keyword search with OLAP-style aggregations, navigation, and reporting. DBPubs starts with keyword search over the content of publications. The publications' metadata such as title, authors, venues, year, and so on, provide traditional OLAP static dimensions, which are combined with dynamic dimensions discovered from the content of the publications in the search result, such as frequent phrases, relevant phrases, and topics. We compute publication ranks based on the link structure between documents, i.e., citations, and aggregate them to find seminal papers, discover trends, and rank authors. We deploy an OLAP tool for multidimensional content exploration through traditional OLAP rollup-drilldown operations on the static and dynamic dimensions, solutions for multi-cube analysis, dynamic navigation of the content, and highlighting of interesting dices of the multidimensional content dataspace.

Published
2024
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9. Multidimensional content eXploration

Author

Simitsis, Alkis, Baid, Akanksha, Sismanis, Yannis, and Reinwald, Berthold

Abstract

Content Management Systems (CMS) store enterprise data such as insurance claims, insurance policies, legal documents, patent applications, or archival data like in the case of digital libraries. Search over content allows for information retrieval, but does not provide users with great insight into the data. A more analytical view is needed through analysis, aggregations, groupings, trends, pivot tables or charts, and so on. Multidimensional Content eXploration (MCX) is about effectively analyzing and exploring large amounts of content by combining keyword search with OLAP-style aggregation, navigation, and reporting. We focus on unstructured data or generally speaking documents or content with limited metadata, as it is typically encountered in CMS. We formally present how CMS content and metadata should be organized in a well-defined multidimensional structure, so that sophisticated queries can be expressed and evaluated. The CMS metadata provide traditional OLAP static dimensions that are combined with dynamic dimensions discovered from the analyzed keyword search result, as well as measures for document scores based on the link structure between the documents. In addition, we provide means for multidimensional content exploration through traditional OLAP rollupdrilldown operations on the static and dynamic dimensions, solutions for multi-cube analysis and dynamic navigation of the content. We present our prototype, called DBPubs, which stores research publications as documents that can be searched and -most importantly-- analyzed, and explored. Finally, we present experimental results of the efficiency and effectiveness of our approach.

Published
2024
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10. Revisiting ETL Benchmarking: The Case for Hybrid Flows

Author

Simitsis, Alkis, Wilkinson, Kevin, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Nambiar, Raghunath, editor, and Poess, Meikel, editor

Published
2013
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11. Requirement-Driven Creation and Deployment of Multidimensional and ETL Designs

Author

Jovanovic, Petar, Romero, Oscar, Simitsis, Alkis, Abelló, Alberto, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Castano, Silvana, editor, Vassiliadis, Panos, editor, Lakshmanan, Laks V., editor, and Lee, Mong Li, editor

Published
2012
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12. Optimization of Analytic Data Flows for Next Generation Business Intelligence Applications

Author

Dayal, Umeshwar, Wilkinson, Kevin, Simitsis, Alkis, Castellanos, Malu, Paz, Lupita, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Nambiar, Raghunath, editor, and Poess, Meikel, editor

Published
2012
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13. Integrating ETL Processes from Information Requirements

Author

Jovanovic, Petar, Romero, Oscar, Simitsis, Alkis, Abelló, Alberto, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Cuzzocrea, Alfredo, editor, and Dayal, Umeshwar, editor

Published
2012
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14. Optimizing Flows for Real Time Operations Management

Author

Simitsis, Alkis, Gupta, Chetan, Wilkinson, Kevin, Dayal, Umeshwar, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Ailamaki, Anastasia, editor, and Bowers, Shawn, editor

Published
2012
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15. GEM: Requirement-Driven Generation of ETL and Multidimensional Conceptual Designs

Author

Romero, Oscar, Simitsis, Alkis, Abelló, Alberto, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Cuzzocrea, Alfredo, editor, and Dayal, Umeshwar, editor

Published
2011
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16. YeSQL

Author

Foufoulas, Yannis, primary, Simitsis, Alkis, additional, and Ioannidis, Yannis, additional

Published
2022
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17. Leveraging Business Process Models for ETL Design

Author

Wilkinson, Kevin, Simitsis, Alkis, Castellanos, Malu, Dayal, Umeshwar, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Parsons, Jeffrey, editor, Saeki, Motoshi, editor, Shoval, Peretz, editor, Woo, Carson, editor, and Wand, Yair, editor

Published
2010
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18. Rule-Based Management of Schema Changes at ETL Sources

Author

Papastefanatos, George, Vassiliadis, Panos, Simitsis, Alkis, Sellis, Timos, Vassiliou, Yannis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Grundspenkis, Janis, editor, Kirikova, Marite, editor, Manolopoulos, Yannis, editor, and Novickis, Leonids, editor

Published
2010
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22. Benchmarking ETL Workflows

Author

Simitsis, Alkis, Vassiliadis, Panos, Dayal, Umeshwar, Karagiannis, Anastasios, Tziovara, Vasiliki, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Nambiar, Raghunath, editor, and Poess, Meikel, editor

Published
2009
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23. Policy-Regulated Management of ETL Evolution

Author

Papastefanatos, George, Vassiliadis, Panos, Simitsis, Alkis, Vassiliou, Yannis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Spaccapietra, Stefano, editor, Zimányi, Esteban, editor, and Song, Il-Yeol, editor

Published
2009
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24. Ontology-Driven Conceptual Design of ETL Processes Using Graph Transformations

Author

Skoutas, Dimitrios, Simitsis, Alkis, Sellis, Timos, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Spaccapietra, Stefano, editor, Zimányi, Esteban, editor, and Song, Il-Yeol, editor

Published
2009
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25. Ontology-Based Data Sharing in P2P Databases

Author

Skoutas, Dimitrios, Kantere, Verena, Simitsis, Alkis, Sellis, Timos, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Christophides, Vassilis, editor, Collard, Martine, editor, and Gutierrez, Claudio, editor

Published
2008
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26. Design Metrics for Data Warehouse Evolution

Author

Papastefanatos, George, Vassiliadis, Panos, Simitsis, Alkis, Vassiliou, Yannis, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Li, Qing, editor, Spaccapietra, Stefano, editor, Yu, Eric, editor, and Olivé, Antoni, editor

Published
2008
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28. What-If Analysis for Data Warehouse Evolution

Author

Papastefanatos, George, Vassiliadis, Panos, Simitsis, Alkis, Vassiliou, Yannis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Song, Il Yeal, editor, Eder, Johann, editor, and Nguyen, Tho Manh, editor

Published
2007
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29. Flexible and Customizable NL Representation of Requirements for ETL processes

Author

Skoutas, Dimitrios, Simitsis, Alkis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Kedad, Zoubida, editor, Lammari, Nadira, editor, Métais, Elisabeth, editor, Meziane, Farid, editor, and Rezgui, Yacine, editor

Published
2007
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30. ETL Workflows: From Formal Specification to Optimization

Author

Sellis, Timos K., Simitsis, Alkis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Ioannidis, Yannis, editor, Novikov, Boris, editor, and Rachev, Boris, editor

Published
2007
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31. Pattern-Based Query Answering

Author

Simitsis, Alkis, Koutrika, Georgia, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Grust, Torsten, editor, Höpfner, Hagen, editor, Illarramendi, Arantza, editor, Jablonski, Stefan, editor, Mesiti, Marco, editor, Müller, Sascha, editor, Patranjan, Paula-Lavinia, editor, Sattler, Kai-Uwe, editor, Spiliopoulou, Myra, editor, and Wijsen, Jef, editor

Published
2006
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32. An Enhanced Search Interface for Information Discovery from Digital Libraries

Author

Koutrika, Georgia, Simitsis, Alkis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Gonzalo, Julio, editor, Thanos, Costantino, editor, Verdejo, M. Felisa, editor, and Carrasco, Rafael C., editor

Published
2006
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33. Comprehensible Answers to Précis Queries

Author

Simitsis, Alkis, Koutrika, Georgia, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Dubois, Eric, editor, and Pohl, Klaus, editor

Published
2006
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35. SheerMP: Optimized Streaming Analytics-as-a-Service over Multi-site Multi-platform Settings

Author

Stamatakis, George, Kontaxakis, Antonios, Simitsis, Alkis, Giatrakos, Nikos, and Deligiannakis, Antonios

Subjects
Big Data, Optimization, Analytics-as-a-Service, Apache Kafka, Apache Spark, Data Streams, Apache Flink, Resource Allocation, Software Architectures
Abstract

Analytics are in the core of many emerging applications and can greatly benefit from the abundance of data and the progress in the processing capabilities of modern hardware. Still, new challenges arise with the extreme complexity of deciding how to execute analytics workflows given the plethora of choices of various cloud providers, the fragmented nature of diverse Big Data technologies, and the difficult task of resource provisioning to dynamically satisfy the demands of running streaming analytics over time. In this paper, we demonstrate a prototype system that optimizes streaming analytics workflows across Big Data platforms and computer clusters. Our system is the first that (i) considers a multi-user setup, (ii) examines the availability of multiple (potentially, geo-dispersed) compute choices, and (iii) provides a holistic framework covering a wide variety of practical optimization and adaptive resource allocation scenarios over a variety of streaming Big Data platforms

Published
2022
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36. Workflow Based Security Incident Management

Author

Belsis, Meletis A., Simitsis, Alkis, Gritzalis, Stefanos, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Bozanis, Panayiotis, editor, and Houstis, Elias N., editor

Published
2005
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37. Blueprints and Measures for ETL Workflows

Author

Vassiliadis, Panos, Simitsis, Alkis, Terrovitis, Manolis, Skiadopoulos, Spiros, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Delcambre, Lois, editor, Kop, Christian, editor, Mayr, Heinrich C., editor, Mylopoulos, John, editor, and Pastor, Oscar, editor

Published
2005
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38. Graph-Based Modeling of ETL Activities with Multi-level Transformations and Updates

Author

Simitsis, Alkis, Vassiliadis, Panos, Terrovitis, Manolis, Skiadopoulos, Spiros, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Tjoa, A Min, editor, and Trujillo, Juan, editor

Published
2005
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40. A Framework for the Design of ETL Scenarios

Author

Vassiliadis, Panos, Simitsis, Alkis, Georgantas, Panos, Terrovitis, Manolis, Goos, Gerhard, editor, Hartmanis, Juris, editor, van Leeuwen, Jan, editor, Eder, Johann, editor, and Missikoff, Michele, editor

Published
2003
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41. On the Logical Modeling of ETL Processes

Author

Vassiliadis, Panos, Simitsis, Alkis, Skiadopoulos, Spiros, Goos, Gerhard, editor, Hartmanis, Juris, editor, van Leeuwen, Jan, editor, Pidduck, Anne Banks, editor, Ozsu, M. Tamer, editor, Mylopoulos, John, editor, and Woo, Carson C., editor

Published
2002
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43. Extreme-Scale Interactive Cross-Platform Streaming Analytics – The INFORE Approach

Author

Deligiannakis, Antonios, Giatrakos, Nikos, Kotidis, Yannis, Samoladas, Vasilis, and Simitsis, Alkis

Subjects
Extreme scale, Big Data, Interactivity, Cross-platform, Processing capability, Prototype system, cross-platform analytics, data streams, Work-flows, Added values, interactive analytics, Emerging applications
Abstract

Nowadays, analytics are at the core of many emerging applications and can greatly benefit from the abundance of data and the progress in the processing capabilities of modern hardware. Still, new challenges arise with the extreme complexity of designing applications to exploit in full the potential of such offerings. In this work, we describe the main challenges in delivering advanced, cross-platform, streaming analytics at scale with the primary goal of interactivity. We present the architecture of a prototype system designed from scratch to tackle such challenges and we describe the internals of its components. Finally, we discuss key added-value synergies upon serving target analytics workflows in real-world applications and present a preliminary performance evaluation., http://ceur-ws.org/Vol-2929/paper2.pdf

Published
2021
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45. Preface to the Industrial Track

Author

Simitsis, Alkis, Van Mingroot, Hans, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, De Troyer, Olga, editor, Bauzer Medeiros, Claudia, editor, Billen, Roland, editor, Hallot, Pierre, editor, Simitsis, Alkis, editor, and Van Mingroot, Hans, editor

Published
2011
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49. Meshing streaming updates with persistent data in an active data warehouse

Author

Polyzotis, Neoklis, Skiadopoulos, Spiros, Vassiliadis, Panos, Simitsis, Alkis, and Frantzell, Nils-Erik

Subjects
Algorithms -- Usage, Data warehousing -- Management, Streaming media -- Management, Knowledge management -- Research, Company business management, Algorithm, Data warehousing/data mining, Streaming media technology, Knowledge management, Business, Computers, Electronics, Electronics and electrical industries
Abstract

Active Data Warehousing has emerged as an alternative to conventional warehousing practices in order to meet the high demand of applications for up-to-date information. In a nutshell, an active warehouse is refreshed online and thus achieves a higher consistency between the stored information and the latest data updates. The need for online warehouse refreshment introduces several challenges in the implementation of data warehouse transformations, with respect to their execution time and their overhead to the warehouse processes. In this paper, we focus on a frequently encountered operation in this context, namely, the join of a fast stream S of source updates with a disk-based relation R, under the constraint of limited memory. This operation lies at the core of several common transformations such as surrogate key assignment, duplicate detection, or identification of newly inserted tuples. We propose a specialized join algorithm, termed mesh join (MESH JOIN), which compensates for the difference in the access cost of the two join inputs by 1) relying entirely on fast sequential scans of R and 2) sharing the I/O cost of accessing R across multiple tuples of S. We detail the MESHJOIN algorithm and develop a systematic cost model that enables the tuning of MESHJOIN for two objectives: maximizing throughput under a specific memory budget or minimizing memory consumption for a specific throughput. We present an experimental study that validates the performance of MESH JOIN on synthetic and real-life data. Our results verify the scalability of MESHJOIN to fast streams and large relations and demonstrate its numerous advantages over existing join algorithms. Index Terms--Active data warehouse, join, MESH JOIN, streams, relations.

Published
2008

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