Selected papers of the 9th annual ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
The LyriC language: querying constraint objects
SIGMOD '95 Proceedings of the 1995 ACM SIGMOD international conference on Management of data
Variable independence and aggregation closure
PODS '96 Proceedings of the fifteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Relational expressive power of constraint query languages
Journal of the ACM (JACM)
Journal of Computer and System Sciences
Relational queries over interpreted structures
Journal of the ACM (JACM)
SIAM Journal on Computing
On the expressiveness of linear-constraint query languages for spatial databases
Theoretical Computer Science
Constraint Databases
Constraint Programming and Database Query Languages
TACS '94 Proceedings of the International Conference on Theoretical Aspects of Computer Software
Linear vs Polynomial Constraints in Database Query Languages
PPCP '94 Proceedings of the Second International Workshop on Principles and Practice of Constraint Programming
Linear Constraint Query Languages: Expressive Power and Complexity
LCC '94 Selected Papers from the International Workshop on Logical and Computational Complexity
Eucil, Tarski, and Engler Encompassed (Preliminary Report)
DBLP-6 Proceedings of the 6th International Workshop on Database Programming Languages
DEDALE, A Spatial Constraint Database
DBLP-6 Proceedings of the 6th International Workshop on Database Programming Languages
On the Expressiveness of First-Order Constraint Languages
Proceedings of the ESPRIT WG CONTESSA Workshop on Constraint Databases and Applications
A representation independent language for planar spatial databases with Euclidean distance
Journal of Computer and System Sciences
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We exhibit a coordinate-based language, called PFOL, which is sound for the linear queries computable in first-order logic over the reals and extends the latter's restriction to linear arithmetic. To evaluate its expressive power, we first consider PFOL-finite, the PFOL programs that compute finite outputs upon finite inputs. In order to study this fragment of PFOL, we also define an equivalent syntactical language, called SPFOL. We show that SPFOL has the same expressive power as SafeEuql (S. Cluet, R. Hull (Eds.), Proceedings of the Sixth International Workshop on Database Programming Languages, Lecture Notes in Computer Science, Vol. 1369, Springer, Berlin, 1997, pp. 1-24), whence all ruler-and-compass constructions in the plane on finite sets of points can be expressed in SPFOL. This result gives a geometrical justification of SPFOL, and, hence, also of PFOL-finite. Then, we define finite representations for arbitrary semi-linear sets and show that there are PFOL programs for both the encoding and the decoding. This result is used (i) to identify a broad, natural class of FO + poly-expressible linear queries of which we show equivalence with the class of PFOL-expressible queries, and (ii) to establish a general theorem about lifting query languages on finite databases to query languages on arbitrary linear databases. This theorem is applied to a recent result of Benedikt and Libkin (SIAM J. Comput. 29 (2000) 1652-1682) from finite to arbitrary semi-linear sets, yielding the existence of a natural, syntactically definable fragment of FO + poly sound and complete for all FO + poly-expressible linear queries.