Query optimization by semantic reasoning
Query optimization by semantic reasoning
Miranda: a non-strict functional language with polymorphic types
Proc. of a conference on Functional programming languages and computer architecture
Optimization of nested SQL queries revisited
SIGMOD '87 Proceedings of the 1987 ACM SIGMOD international conference on Management of data
A rule-based view of query optimization
SIGMOD '87 Proceedings of the 1987 ACM SIGMOD international conference on Management of data
Optimizing and executing DAPLEX queries using Prolog
The Computer Journal - On concurrent logic programming
Object-oriented databases: a semantic data model approach
Object-oriented databases: a semantic data model approach
Extensible/rule based query rewrite optimization in Starburst
SIGMOD '92 Proceedings of the 1992 ACM SIGMOD international conference on Management of data
The functional data model and the data languages DAPLEX
ACM Transactions on Database Systems (TODS)
On optimizing an SQL-like nested query
ACM Transactions on Database Systems (TODS)
Guest Editor Introduction: Functional Approach to Intelligent Information Systems
Journal of Intelligent Information Systems - Special issue on functional approach to intelligent information systems
The Evolving Role of Constraints in the Functional Data Model
Journal of Intelligent Information Systems - Special issue on functional approach to intelligent information systems
Range nesting: a fast method to evaluate quantified queries
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
Processing queries with quantifiers a horticultural approach
PODS '83 Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems
A Prolog Interface to a Functional Data Model Database
EDBT '88 Proceedings of the International Conference on Extending Database Technology: Advances in Database Technology
Distributing Semantic Constraints Between Heterogeneous Databases
ICDE '97 Proceedings of the Thirteenth International Conference on Data Engineering
Optimization of Nested Queries in a Distributed Relational Database
VLDB '84 Proceedings of the 10th International Conference on Very Large Data Bases
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
A Data Transformation System for Biological Data Sources
VLDB '95 Proceedings of the 21th International Conference on Very Large Data Bases
Optimizing Queries with Universal Quantification in Object-Oriented and Object-Relational Databases
VLDB '97 Proceedings of the 23rd International Conference on Very Large Data Bases
A Modular Compiler Architecture for a Data Manipulation Language
BNCOD 14 Proceedings of the 14th British National Conference on Databases: Advances in Databases
Using the Functional Data Model to Integrate Distributed Biological Data Sources
SSDBM '96 Proceedings of the Eighth International Conference on Scientific and Statistical Database Management
Improved Unnesting Algorithms for Join Aggregate SQL Queries
VLDB '92 Proceedings of the 18th International Conference on Very Large Data Bases
A schema-based approach to building a bioinformatics database federation
BIBE '00 Proceedings of the 1st IEEE International Symposium on Bioinformatics and Biomedical Engineering
Integrating life sciences data-with a little Garlic
BIBE '00 Proceedings of the 1st IEEE International Symposium on Bioinformatics and Biomedical Engineering
Query Processing in the TAMBIS Bioinformatics Source Integration System
SSDBM '99 Proceedings of the 11th International Conference on Scientific and Statistical Database Management
Kleisli, a functional query system
Journal of Functional Programming
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Transforming queries for efficient execution is particularly important in federated database systems since a more efficient execution plan can require many fewer data requests to be sent to the component databases. Also, it is important to do as much as possible of the selection and processing close to where the data are stored, making best use of facilities provided by the federation's component database management systems. In this paper we address the problem of processing complex queries including quantifiers, which have to be executed against different databases in an expanding heterogeneous federation. This is done by transforming queries within a mediator for global query improvement, and within wrappers to make the best use of the query processing capabilities of external databases. Our approach is based on pattern matching and query rewriting. We introduce a high level language for expressing rewrite rules declaratively, and demonstrate the use and flexibility of such rules in improving query performance for existentially quantified subqueries. Extensions to this language that allow generic rewrite rules to be expressed are also presented. The value of performing final transformations within a wrapper for a given remote database is shown in several examples that use AMOS II—an SQL3-like system.