On compiling queries in recursive first-order databases
Journal of the ACM (JACM)
Interfacing PROLOG and relational data base management systems
Proc. of the ICOD-2 workshop on New applications of data bases
Expert database systems: a database perspective
Proceedings from the first international workshop on Expert database systems
What makes a knowledge base knowledgeable? A view of databases from the knowledge level
Proceedings from the first international workshop on Expert database systems
Prolog: a database query language for all seasons
Proceedings from the first international workshop on Expert database systems
Proceedings from the first international workshop on Expert database systems
Towards an integrated database-Prolog system
Proceedings from the first international workshop on Expert database systems
Heuristic search in database systems
Proceedings from the first international workshop on Expert database systems
External semantic query simplification: a graph-theoretic approach and its implementation in Prolog
Proceedings from the first international workshop on Expert database systems
Implementation of logiclal query languages for databases (abstract only)
SIGMOD '85 Proceedings of the 1985 ACM SIGMOD international conference on Management of data
Some high level language constructs for data of type relation
ACM Transactions on Database Systems (TODS)
Logic and Databases: A Deductive Approach
ACM Computing Surveys (CSUR)
Implementation of integrity constraints and views by query modification
SIGMOD '75 Proceedings of the 1975 ACM SIGMOD international conference on Management of data
The Science of Programming
Range nesting: a fast method to evaluate quantified queries
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
Horn clauses and the fixpoint query hierarchy
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
Recursive Data Models for Non-Conventional Database Applications
Proceedings of the First International Conference on Data Engineering
Language Support for Office Modelling
VLDB '84 Proceedings of the 10th International Conference on Very Large Data Bases
Constraint Equations: Declarative Expression of Constraints With Automatic Enforcement
VLDB '84 Proceedings of the 10th International Conference on Very Large Data Bases
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Although the goals and means of rule-based and data-based systems are too different to be fully integrated at the present time, it seems appropriate to investigate a closer integration of language constructs and a better cooperation of execution models for both kinds of approaches. In this paper we propose a new language construct called constructor that allows the definition of new relations from existing ones by means of recursion. The constructor is semantically defined by the least fixed point of a set expression and blends well both with a strongly typed modular programming language and with a relational calculus query formalism. Moreover, it is shown to provide expressive power at least equivalent to the declarative semantics of PROLOG while avoiding some disadvantages of it, for example, poor modularity and infinite loops. Furthermore, the constructor is set-oriented thus allowing more efficient implementation techniques than those available through proof-theoretic methods typical of a rule-based approach.