Abstract
In databases, queries are usually defined on complete databases. In this paper we introduce and motivate the notion of extended queries that are defined on incomplete databases. We argue that the language of extended logic program is appropriate for representing extended queries. We show through examples that given a query, a particular extension of it has important characteristics which corresponds to removal of the CWA from the original specification of the query. We refer to this particular extension as the expansion of the original query. Normally queries are expressed as general logic programs. We develop an algorithm that given a general logic program (satisfying certain syntactic properties) expressing a query constructs an extended logic program that expresses the expanded query. The extended logic program is referred to as the interpolation of the given general logic program.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 195-230 |
| Number of pages | 36 |
| Journal | Journal of Logic Programming |
| Volume | 35 |
| Issue number | 3 |
| State | Published - Jun 1998 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Logic
Cite this
Expanding queries to incomplete databases by interpolating general logic programs. / Baral, Chitta; Gelfond, Michael; Kosheleva, Olga.
In: Journal of Logic Programming, Vol. 35, No. 3, 06.1998, p. 195-230.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Expanding queries to incomplete databases by interpolating general logic programs
AU - Baral, Chitta
AU - Gelfond, Michael
AU - Kosheleva, Olga
PY - 1998/6
Y1 - 1998/6
N2 - In databases, queries are usually defined on complete databases. In this paper we introduce and motivate the notion of extended queries that are defined on incomplete databases. We argue that the language of extended logic program is appropriate for representing extended queries. We show through examples that given a query, a particular extension of it has important characteristics which corresponds to removal of the CWA from the original specification of the query. We refer to this particular extension as the expansion of the original query. Normally queries are expressed as general logic programs. We develop an algorithm that given a general logic program (satisfying certain syntactic properties) expressing a query constructs an extended logic program that expresses the expanded query. The extended logic program is referred to as the interpolation of the given general logic program.
AB - In databases, queries are usually defined on complete databases. In this paper we introduce and motivate the notion of extended queries that are defined on incomplete databases. We argue that the language of extended logic program is appropriate for representing extended queries. We show through examples that given a query, a particular extension of it has important characteristics which corresponds to removal of the CWA from the original specification of the query. We refer to this particular extension as the expansion of the original query. Normally queries are expressed as general logic programs. We develop an algorithm that given a general logic program (satisfying certain syntactic properties) expressing a query constructs an extended logic program that expresses the expanded query. The extended logic program is referred to as the interpolation of the given general logic program.
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UR - http://www.scopus.com/inward/citedby.url?scp=0032097629&partnerID=8YFLogxK
M3 - Article
VL - 35
SP - 195
EP - 230
JO - Journal of Logic Programming
JF - Journal of Logic Programming
SN - 1567-8326
IS - 3
ER -