Database Relations with Null Values (1984) [53 citations — 0 self]
by
Carlo Zaniolo
Add To MetaCart
Popular Tags
No tags have been applied to this document.
BibTeX | Add To MetaCart
@MISC{Zaniolo84databaserelations,
author = {Carlo Zaniolo},
title = {Database Relations with Null Values},
year = {1984}
}
author = {Carlo Zaniolo},
title = {Database Relations with Null Values},
year = {1984}
}
Years of Citing Articles
Bookmarks
OpenURL
Abstract:
this paper we briefly review some of these issues and then concentrate on the problem of generalizing the formal framework of the relational data model to include null values. A basic problem with null values is that they have many plausible interpretations. The ANSI/SPARC interim report, for instance, cites 14 different manifestations of nulls. Most authors, however, agree that the various manifestations of nulls can be reduced to two basic interpretations. These are: (a) the unknown interpretation: a value exists but it is not known; and lb) the nonexistent interpretation: a value does not exist
