Tansel, Abdullah UzRivero, L. C.Doorn, J. H.Ferraggine, V. E.2018-04-122018-04-1220059781591405603http://hdl.handle.net/11693/37847The paper discusses modelling temporal variation of data in the context of the relational data model. This is done by employing time-stamps, which leads to two possible approaches: adding time-stamps to tuples and using first normal-form (1NF) relations, and adding time-stamps to attributes and using non-first normal form (NINF) relations. Modelling temporal data according to each approach with their respective data-manipulation operations are covered. This is followed by a discussion that includes the advantages and expressive power of each approach, the classification of temporal databases, and the handling of retroactive and postactive changes.EnglishDatabasesTemporal dataModellingrelational data modelRelational data modelBook Chapter10.4018/978-1-59140-560-3.ch0639781591407959