Attribute domain
In computing, the attribute domain is the set of values allowed in an attribute.[1]
For example:
Rooms in hotel (1-300) Age (1-99) Married (yes or no) Nationality (Nepalese, Indian, American, or British) Colors (Red, Yellow, Green)
For the relational model it is a requirement that each part of a tuple be atomic.[2] The consequence is that each value in the tuple must be of some basic type, like a string or an integer. For the elementary type to be atomic it cannot be broken into more pieces. Alas, the domain is an elementary type, and attribute domain the domain a given attribute belongs to an abstraction belonging to or characteristic of an entity.
References
- ↑ Levene, Mark; Loizou, George (1999), A Guided Tour of Relational Databases and Beyond, Springer, p. 72, ISBN 9781852330088.
- ↑ Narang, Rajesh (2011), Database Management Systems, PHI Learning Pvt. Ltd., p. 70, ISBN 9788120343139.
This article is issued from Wikipedia - version of the Saturday, March 07, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.