Query Workflows over Web Data sources

Most of the information that is needed for daily tasks is available on the Web. The main problem is often not to get the information, but to process it efficiently and appropriately in an automatic way. Often it is easier to design the process how to solve such a problem than stating a single query. Furthermore, most of the data is not immediately available for querying via e.g. query languages like SQL or XQuery, but kept in the Deep Web, which consists of dynamically generated result pages, which can only be queried interactively via Web forms.

Tailoring process algebras like Milner's Calculus of Communicating Systems (CCS) to relational dataflow makes them a natural candidate for specifying such data-oriented workflows in a declarative way. In addition to the classical evaluation of relational operator trees, the combination with the CCS control structures provides (guarded) alternatives and test-based iterations using recursive process fragment definitions. For the actual atomic constituents of the process, queries to Web services and Deep Web sources are supported. Additionally, abstract datatypes, e.g., graphs, can be embedded.

Project Members:

• Dr.-Ing. Thomas Hornung

Publications

• Thomas Hornung:
  Query Workflows over Web Data Sources
  Ph.D. thesis, October 2010, Freiburg (Germany)
• Thomas Hornung, Wolfgang May, Daniel Schubert:
  A Configurable Graph Data Type for Online Exploration of Web Data
  In 1^st Workshop on Querying Graph Structured Data (GraphQ 2010), September 2010, Novi Sad (Serbia)
• Thomas Hornung, Wolfgang May:
  Semantic Annotations and Querying of Web Data Sources
  In Proc. of the 17^th International Conference on Cooperative Information Systems (CoopIS 2009), November 2009, Vilamoura (Portugal).
• Thomas Hornung, Wolfgang May:
  Ontology-Based Support for Graph Algorithms in Online Exploration Workflows (Poster)
  In Proc. of the 8^th International Conference on Ontologies, DataBases, and Applications of Semantics (ODBASE 2009), November 2009, Vilamoura (Portugal).
• Thomas Hornung, Wolfgang May:
  Process Algebra-Based Query Workflows
  In Proc. of the 21^st International Conference on Advanced Information Systems (CAISE), June 2009, Amsterdam (The Netherlands).
• Thomas Hornung, Wolfgang May:
  Deep Web Queries in a Semantic Web Environment
  In 2^nd Workshop on Advances in Accessing Deep Web (ADW 2009), co-located with 12^th International Conference on Business Information Systems (BIS 2009), April 2009, Poznan (Poland).
• Yang Wang, Thomas Hornung:
  Deep Web Navigation by Example
  In Proc. of the 1^st Workshop on Advances in Accessing Deep Web (ADW 2008), co-located with the 11^th International Conference on Business Information Systems (BIS 2008), May 2008, Innsbruck, (Austria).
• Thomas Hornung, Kai Simon, Georg Lausen:
  Mashups over the Deep Web
  In Lecture Notes in Business Information Processing, Volume 18, WEBIST (Revised Selected Papers), pp. 228 - 241.
• Thomas Hornung, Kai Simon, Georg Lausen:
  Mashing Up the Deep Web - Research in Progress
  In Proc. of the 4^th International Conference on Web Information Systems and Technologies (WEBIST), May 2008, Madeira (Portugal).