Optimization of join operations in horizontally partitioned database systems
ACM Transactions on Database Systems (TODS)
Safety and translation of relational calculus
ACM Transactions on Database Systems (TODS)
Answering queries using templates with binding patterns (extended abstract)
PODS '95 Proceedings of the fourteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Query reformulation for dynamic information integration
Journal of Intelligent Information Systems - Special issue on intelligent integration of information
Capability based mediation in TSIMMIS
SIGMOD '98 Proceedings of the 1998 ACM SIGMOD international conference on Management of data
Computing capabilities of mediators
SIGMOD '99 Proceedings of the 1999 ACM SIGMOD international conference on Management of data
The complexity of ordering subgoals
Proceedings of the seventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
An algorithm for ordering subgoals in NAIL?
Proceedings of the seventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Principles of Database and Knowledge-Base Systems: Volume II: The New Technologies
Principles of Database and Knowledge-Base Systems: Volume II: The New Technologies
Querying Heterogeneous Information Sources Using Source Descriptions
VLDB '96 Proceedings of the 22th International Conference on Very Large Data Bases
NP-Completeness: A Retrospective
ICALP '97 Proceedings of the 24th International Colloquium on Automata, Languages and Programming
Processing first-order queries under limited access patterns
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Integration of heterogeneous knowledge sources in the CALO query manager
OTM'05 Proceedings of the 2005 OTM Confederated international conference on On the Move to Meaningful Internet Systems
Rewriting queries using views with access patterns under integrity constraints
ICDT'05 Proceedings of the 10th international conference on Database Theory
Optimization of multi-domain queries on the web
Proceedings of the VLDB Endowment
Semantic Annotations and Querying of Web Data Sources
OTM '09 Proceedings of the Confederated International Conferences, CoopIS, DOA, IS, and ODBASE 2009 on On the Move to Meaningful Internet Systems: Part I
Proceedings of the 13th International Conference on Extending Database Technology
Chapter 10: join methods and query optimization
Search Computing
| Hi-index | 0.00 |
In this paper, we study the problem of ordering subgoals under binding pattern restrictions for queries posed as nonrecursive Datalog programs. We prove that despite their limited expressive power, the problem is computationally hard—PSPACE-complete in the size of the nonrecursive Datalog program even for fairly restricted cases. As a practical solution to this problem, we develop an asymptotically optimal algorithm that runs in time linear in the size of the query plan. We also study extensions of our algorithm that efficiently solve other query planning problems under binding pattern restrictions. These problems include conjunctive queries with nested grouping constraints, distributed conjunctive queries, and first-order queries.