Finding Regular Simple Paths in Graph Databases
SIAM Journal on Computing
Answering queries using views (extended abstract)
PODS '95 Proceedings of the fourteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Answering recursive queries using views
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Handbook of formal languages, vol. 1
Query containment for conjunctive queries with regular expressions
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Complexity of answering queries using materialized views
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Rewriting of regular expressions and regular path queries
PODS '99 Proceedings of the eighteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query rewriting for semistructured data
SIGMOD '99 Proceedings of the 1999 ACM SIGMOD international conference on Management of data
WWW '99 Proceedings of the eighth international conference on World Wide Web
Data on the Web: from relations to semistructured data and XML
Data on the Web: from relations to semistructured data and XML
View-based query processing for regular path queries with inverse
PODS '00 Proceedings of the nineteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Introduction To Automata Theory, Languages, And Computation
Introduction To Automata Theory, Languages, And Computation
Optimizing Regular Path Expressions Using Graph Schemas
ICDE '98 Proceedings of the Fourteenth International Conference on Data Engineering
Information Integration Using Logical Views
ICDT '97 Proceedings of the 6th International Conference on Database Theory
ICDT '97 Proceedings of the 6th International Conference on Database Theory
Adding Structure to Unstructured Data
ICDT '97 Proceedings of the 6th International Conference on Database Theory
Tableau Techniques for Querying Information Sources through Global Schemas
ICDT '99 Proceedings of the 7th International Conference on Database Theory
Index Structures for Path Expressions
ICDT '99 Proceedings of the 7th International Conference on Database Theory
An Optimization Technique for Answering Regular Path Queries
Selected papers from the Third International Workshop WebDB 2000 on The World Wide Web and Databases
Answering Regular Path Queries Using Views
ICDE '00 Proceedings of the 16th International Conference on Data Engineering
On the equivalence, containment, and covering problems for the regular and context-free languages
Journal of Computer and System Sciences
New Rewritings and Optimizations for Regular Path Queries
ICDT '03 Proceedings of the 9th International Conference on Database Theory
Optimization Properties for Classes of Conjunctive Regular Path Queries
DBPL '01 Revised Papers from the 8th International Workshop on Database Programming Languages
Regular path queries on graphs with data
Proceedings of the 15th International Conference on Database Theory
Hi-index | 0.00 |
Rewriting queries using views is a powerful technique that has applications in query optimization, data integration, data warehousing etc. Query rewriting in relational databases is by now rather well investigated. However, in the framework of semistructured data the problem of rewriting has received much less attention. In this paper we focus on extracting as much information as possible from algebraic rewritings for the purpose of optimizing regular path queries. The cases when we can find a complete exact rewriting of a query using a set a views are very "ideal." However, there is always information available in the views, even if this information is only partial. We introduce "lower" and "possibility" partial rewritings and provide algorithms for computing them. These rewritings are algebraic in their nature, i.e. we use only the algebraic view definitions for computing the rewritings. This fact makes them a main memory product which can be used for reducing secondary memory and remote access. We give two algorithms for utilizing the partial lower and partial possibility rewritings in the context of query optimization.