Frequency operators for condensative queries over data streams

Ma Lisha, Werner Nutt

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Over a traditional Database Management System (DBMS), the answer to an aggregate query is usually much smaller than the answer to a similar non-aggregate query. Therefore, we call such a query "condensative". Current proposals for declarative query languages over data streams do not support such condensative querying. In order to make existing stream query languages more expressive so that they enable a user both, to state more intuitively interesting queries, and to support condensative querying, we propose a new data stream model, referred to as the sequence model, and an extension to SQL-like query languages by operators that allows one to specify the frequency by which a query returns answer tuples. We show that such frequency operators allow one to express sampling over streams. If combined with existing sliding window operators, they support queries with "jumping windows". We show with a number of examples from a sensor monitoring application how complex queries can be elegantly formulated in a stream query language with frequency operators. © 2005 IEEE.

Original languageEnglish
Title of host publicationProceedings - ICEBE 2005: IEEE International Conference on e-Business Engineering
Number of pages8
Publication statusPublished - 2005
EventProceedings - 10th IEEE International Conference on Computer Vision - Beijing, China
Duration: 17 Oct 200520 Oct 2005


ConferenceProceedings - 10th IEEE International Conference on Computer Vision
Abbreviated titleICCV 2005


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