About Natural Logic

Colmerauer, Alain; Pique, Jean François

doi:10.1007/978-1-4615-8297-7_12

Cited by 13 publications

(3 citation statements)

References 2 publications

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“…Logic languages are close to natural languages. In addition to Codd [1972], who used this argument to support the relational calculus as a yardstick to measure other languages, many linguists have also made this observation; thus querying databases using natural language has been and is a subject of active research [Colmerauer 1973;Colmerauer and Pique 1981;Dahl 1982;Moore 1981;Warren 1981;Woods 1967]. Several authors have questioned Codd's proposal to "define" completeness (i.e., expressiveness) of query languages with reference to a language (relational calculus) whose expressiveness had not been assessed from a semantic viewpoint.…”

Section: Extensions To Query Languagesmentioning

confidence: 95%

Logic and Databases: A Deductive Approach

1984

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The purpose of this paper is to show that logic provides a convenient formalism for studying classical database problems. There are two main parts to the paper, devoted respectively to conventional databases and deductive databases. In the first part, we focus on query languages, integrity modeling and maintenance, query optimization, and data dependencies. The second part deals mainly with the representation and manipulation of deduced facts and incomplete information.

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Section: Extensions To Query Languagesmentioning

confidence: 95%

Logic and Databases: A Deductive Approach

1984

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“…This can serve as a tool in correcting possible errors in users' queries, and to give the user information related to the query asked. 6 Corella et al 7] considered nding the MFSs to conjunctive boolean queries for library searches. Their ward (P, maternity), infected (P,I), contagious (I), staph (I).…”

Section: Introductionmentioning

confidence: 99%

“…A disjoint query is equivalent to the union of several independent queries 6. However, this is not as powerful as identifying a maximally succeeding subquery, as seen in examples in the introduction.…”

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confidence: 99%

Minimization in Cooperative Response to Failing Database Queries

Godfrey

1997

Int. J. Coop. Info. Syst.

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When a query fails, it is more cooperative to identify the cause of failure, rather than just to report the empty answer set. When there is not a cause per se for the query's failure, it is then worthwhile to report the part of the query which failed. To identify a Minimal Failing Subquery (MFS) of the query is the best way to do this. (This MFS is not unique; there may be many of them.) Likewise, to identify a Maximal Succeeding Subquery (XSS) can help a user to recast a new query that leads to a non-empty answer set. Database systems do not provide the functionality of these types of cooperative responses. This may be, in part, because algorithmic approaches to finding the MFSs and the XSSs to a failing query are not obvious. The search space of subqueries is large. Despite work on MFSs in the past, the algorithmic complexity of these identification problems had remained uncharted. This paper shows the complexity profile of MFS and XSS identification. It is shown that there exists a simple algorithm for finding an MFS or an XSS by asking N subsequent queries, in which N is the length of the query. To find more MFSs (or XSSs) can be hard. It is shown that to find N MFSs (or XSSs) is NP-hard. To find k MFSs (or XSSs), for a fixed k, remains polynomial. An optimal algorithm for enumerating MFSs and XSSs, ISHMAEL, is developed and presented. The algorithm has ideal performance in enumeration, finding the first answers quickly, and only decaying toward intractability in a predictable manner as further answers are found. The complexity results and the algorithmic approaches given in this paper should allow for the construction of cooperative facilities which identify MFSs and XSSs for database systems. These results are relevant to a number of problems outside of databases too, and may find further application.

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Cooperative Database Systems

Chu

1999

Wiley Encyclopedia of Electrical and Electronics Engineering

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The sections in this article are Overview Structured Approach for Query Relaxation Automatic Knowledge Acquisition Cooperative Operations A Scalable and Extensible Architecture Performance Evaluation Technology Transfer of Cobase Conclusions Acknowledgments

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About Natural Logic

Cited by 13 publications

References 2 publications

Logic and Databases: A Deductive Approach

Logic and Databases: A Deductive Approach

Minimization in Cooperative Response to Failing Database Queries

Cooperative Database Systems

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