On the possibility of path expressions containing backward navigations in object-oriented databases
✍ Scribed by Nobutaka Suzuki; Minoru Ito; Jun Okui
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 723 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0882-1666
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✦ Synopsis
A path expression in object-oriented databases is an accepted means of navigating over database objects. A backward navigation in a path expression is an operation to find the objects that have a given target object as a given property value. A path expression pd is called possible with respect to a class C if there is a database that contains a path satisfying the following conditions:
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The path starts from an object in C.
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The sequence of the properties on the path coincides with pd.
In this paper, we first present a sound and complete axiomatization for computing a path expression that is possible with respect to a class. Then we present a polynomial-time algorithm that decides whether a path expression is possible with respect to a class.