umu.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
FD Covers and Universal Complements of Simple Projections
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
2012 (Engelska)Ingår i: Foundations of Information and Knowledge Systems -: 7th International Symposium, FoIKS 2012, Kiel, Germany, March 5-9, 2012. Proceedings / [ed] Thomas Lukasiewicz, Attila Sali, Heidelberg: Springer Berlin/Heidelberg, 2012, s. 184-202Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

The constant-complement strategy, in which the admissible updates to a given view are those which hold a second complementary view constant, remains one of the most attractive formalisms for identifying suitable translation mechanisms for updates to views of database schemata. However, in general, it suffers from the drawback that the reflections of view updates to the main schema can depend upon the choice of complement in various ways. To overcome this drawback completely, a special kind of complement, called a universal complement, is required. In this paper, sufficient conditions for the existence of such a complement are established for a classical but nevertheless very important setting — views defined by simple projection of a universal relational schema constrained by functional dependencies (FDs). Certain uniqueness properties of covers of these dependencies prove critical in the characterization. The results are extended to quasi-universal complements, which are unique up to exchange of equivalent attributes, thus recapturing certain situations for which unique covers do not exist.

Ort, förlag, år, upplaga, sidor
Heidelberg: Springer Berlin/Heidelberg, 2012. s. 184-202
Serie
Lecture Notes in Computer Science, ISSN 0302-9743 ; 7153
Nationell ämneskategori
Datorsystem
Identifikatorer
URN: urn:nbn:se:umu:diva-53916DOI: 10.1007/978-3-642-28472-4_11ISBN: 978-3-642-28471-7 (tryckt)OAI: oai:DiVA.org:umu-53916DiVA, id: diva2:514388
Konferens
FoIKS 2012, Kiel, Germany, March 5-9, 2012
Tillgänglig från: 2012-04-09 Skapad: 2012-04-09 Senast uppdaterad: 2018-06-08Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltext

Personposter BETA

Hegner, Stephen

Sök vidare i DiVA

Av författaren/redaktören
Hegner, Stephen
Av organisationen
Institutionen för datavetenskap
Datorsystem

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetricpoäng

doi
isbn
urn-nbn
Totalt: 60 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf