Loading...
Please wait, while we are loading the content...
Similar Documents
Null Values in Object Bases : Pulling Out the Head from the Sand
| Content Provider | Semantic Scholar |
|---|---|
| Author | Subieta, Kazimierz Kambayashi, Yahiko Lowski, Jacek Leszczy Ulidowski, Irek |
| Copyright Year | 1996 |
| Abstract | We address the problem of null values and other forms of irregular data in object-oriented databases. This problem is important because of such aspects of modern database technologies as conceptual modeling, database design, schema evolution, interoperability, integration of data from heterogeneous sources, data warehousing, as well as reliability, maintenance and documentation of databases and application programs. We analyze various approaches to null values postulated by the relational school, in particular the SQL approach and the default values. In response we propose a new universal approach to irregular data based on the idea of absent objects. We believe that our method solves the diiculties encountered in SQL. Moreover , it covers union types and can be smoothly combined with the idea of default values. We discuss the implications of the approach to query languages, and brieey introduce a new approach to polymorphic typing of irregular data. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.ipipan.waw.pl/~subieta/oqlpl/nullvalu.ps.gz |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
