Functional requirements for historical and interval extensions to the relational model

dc.contributor.author	Lorentzos, NA	en
dc.contributor.author	Manolopoulos, Y	en
dc.date.accessioned	2014-06-06T06:42:58Z
dc.date.available	2014-06-06T06:42:58Z
dc.date.issued	1995	en
dc.identifier.issn	0169023X	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/919
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0029387002&partnerID=40&md5=73b8a39e6e8f828891cdb32145d4c5b3	en
dc.subject	Data model	en
dc.subject	Data type	en
dc.subject	Historical data	en
dc.subject	Historical database	en
dc.subject	Interval data	en
dc.subject	Interval database	en
dc.subject	Time interval	en
dc.subject	Time point	en
dc.subject	Valid time data	en
dc.subject.other	Data structures	en
dc.subject.other	Distributed database systems	en
dc.subject.other	History	en
dc.subject.other	Mathematical models	en
dc.subject.other	Relational database systems	en
dc.subject.other	Social sciences	en
dc.subject.other	Social sciences computing	en
dc.subject.other	Time measurement	en
dc.subject.other	Data type	en
dc.subject.other	Historical data	en
dc.subject.other	Historical database	en
dc.subject.other	Interval data	en
dc.subject.other	Interval database	en
dc.subject.other	Valid time data	en
dc.subject.other	Data processing	en
dc.title	Functional requirements for historical and interval extensions to the relational model	en
heal.type	journalArticle	en
heal.publicationDate	1995	en
heal.abstract	In recent years a lot of divergent approaches have been proposed for the management of Valid Time (Historical) data. However, no systematic effort has been reported, concerning the identification of the properties of such a model. In the present work, it is initially shown that all proposed Valid Time (VT) models can be applied to areas of practical interest, not related to VT data management. All VT models are also classified with respect to two orthogonal parameters, the way time is represented, and the level at which it is incorporated (tuple or attribute). This enables to identify that two reference VT models can be specified, VT-1NF, a simple extension to the conventional relational model and VT-NESTED, a more general one, which supports, in addition, relation-valued attributes. The properties of these models are identified. Two more reference interval relational models are proposed, I-1NF and I-NESTED, which support any type of interval data. I-NESTED is the most general, in that it can be applied to all the areas in which all others are applicable. Results are also reported, concerning the evaluation of all VT models. © 1995.	en
heal.journalName	Data and Knowledge Engineering	en
dc.identifier.issue	1	en
dc.identifier.volume	17	en
dc.identifier.spage	59	en
dc.identifier.epage	86	en