Window specification over data streams

Patroumpas, K; Sellis, T

dc.contributor.author	Patroumpas, K	en
dc.contributor.author	Sellis, T	en
dc.date.accessioned	2014-03-01T02:44:22Z
dc.date.available	2014-03-01T02:44:22Z
dc.date.issued	2006	en
dc.identifier.issn	0302-9743	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/31781
dc.subject	Continuous Query	en
dc.subject	Data Stream	en
dc.subject	Query Language	en
dc.subject	Query Optimization	en
dc.subject.classification	Computer Science, Theory & Methods	en
dc.subject.other	Data stream	en
dc.subject.other	Query optimization	en
dc.subject.other	Window specification	en
dc.subject.other	Boolean algebra	en
dc.subject.other	Data structures	en
dc.subject.other	Data transfer	en
dc.subject.other	Mathematical operators	en
dc.subject.other	Query languages	en
dc.subject.other	Semantics	en
dc.subject.other	Set theory	en
dc.subject.other	Computer operating systems	en
dc.title	Window specification over data streams	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1007/11896548_35	en
heal.identifier.secondary	http://dx.doi.org/10.1007/11896548_35	en
heal.language	English	en
heal.publicationDate	2006	en
heal.abstract	Several query languages have been proposed for managing data streams in modern monitoring applications. Continuous queries expressed in these languages usually employ windowing constructs in order to extract finite portions of the potentially unbounded stream. Explicitly or not, window specifications rely on ordering. Usually, timestamps are attached to all tuples flowing into the system as a means to provide ordered access to data items. Several window types have been implemented in stream prototype systems, but a precise definition of their semantics is still lacking. In this paper, we describe a formal framework for expressing windows in continuous queries over data streams. After classifying windows according to their basic characteristics, we give algebraic expressions for the most significant window types commonly appearing in applications. As an essential step towards a stream algebra, we then propose formal definitions for the windowed analogs of typical relational operators, such as join, union or aggregation, and we identify several properties useful to query optimization. © IFIP International Federation for Information Processing 2006.	en
heal.publisher	SPRINGER-VERLAG BERLIN	en
heal.journalName	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)	en
heal.bookName	LECTURE NOTES IN COMPUTER SCIENCE	en
dc.identifier.doi	10.1007/11896548_35	en
dc.identifier.isi	ISI:000241726200035	en
dc.identifier.volume	4254 LNCS	en
dc.identifier.spage	445	en
dc.identifier.epage	464	en