Optimization of real conjunctive queries
PODS '93 Proceedings of the twelfth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Answering queries using views (extended abstract)
PODS '95 Proceedings of the fourteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
An overview of data warehousing and OLAP technology
ACM SIGMOD Record
Rewriting aggregate queries using views
PODS '99 Proceedings of the eighteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Answering complex SQL queries using automatic summary tables
SIGMOD '00 Proceedings of the 2000 ACM SIGMOD international conference on Management of data
Generating efficient plans for queries using views
SIGMOD '01 Proceedings of the 2001 ACM SIGMOD international conference on Management of data
Optimizing queries using materialized views: a practical, scalable solution
SIGMOD '01 Proceedings of the 2001 ACM SIGMOD international conference on Management of data
Database Systems: The Complete Book
Database Systems: The Complete Book
Access path selection in a relational database management system
SIGMOD '79 Proceedings of the 1979 ACM SIGMOD international conference on Management of data
ICDE '97 Proceedings of the Thirteenth International Conference on Data Engineering
Optimizing Queries with Materialized Views
ICDE '95 Proceedings of the Eleventh International Conference on Data Engineering
VLDB '98 Proceedings of the 24rd International Conference on Very Large Data Bases
Aggregate-Query Processing in Data Warehousing Environments
VLDB '95 Proceedings of the 21th International Conference on Very Large Data Bases
Answering Queries with Aggregation Using Views
VLDB '96 Proceedings of the 22th International Conference on Very Large Data Bases
VLDB '97 Proceedings of the 23rd International Conference on Very Large Data Bases
Query Transformation for PSJ-Queries
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
The GMAP: a versatile tool for physical data independence
The VLDB Journal — The International Journal on Very Large Data Bases
MiniCon: A scalable algorithm for answering queries using views
The VLDB Journal — The International Journal on Very Large Data Bases
Answering queries using views: A survey
The VLDB Journal — The International Journal on Very Large Data Bases
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Stacked indexed views in microsoft SQL server
Proceedings of the 2005 ACM SIGMOD international conference on Management of data
Selecting and using views to compute aggregate queries
ICDT'05 Proceedings of the 10th international conference on Database Theory
Using views to generate efficient evaluation plans for queries
Journal of Computer and System Sciences
Compiling mappings to bridge applications and databases
Proceedings of the 2007 ACM SIGMOD international conference on Management of data
Compiling mappings to bridge applications and databases
ACM Transactions on Database Systems (TODS)
Complete and Equivalent Query Rewriting Using Views
APWeb/WAIM '09 Proceedings of the Joint International Conferences on Advances in Data and Web Management
Equivalence of SQL queries in presence of embedded dependencies
Proceedings of the twenty-eighth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Systematic Exploration of Efficient Query Plans for Automated Database Restructuring
ADBIS '09 Proceedings of the 13th East European Conference on Advances in Databases and Information Systems
Computing certain answers in the presence of dependencies
Information Systems
On tree pattern query rewriting using views
WISE'07 Proceedings of the 8th international conference on Web information systems engineering
Efficient processing of monotonic linear progressive queries via dynamic materialized views
Proceedings of the 2010 Conference of the Center for Advanced Studies on Collaborative Research
A materialized-view based technique to optimize progressive queries via dependency analysis
Proceedings of the 2011 Conference of the Center for Advanced Studies on Collaborative Research
CASCON '12 Proceedings of the 2012 Conference of the Center for Advanced Studies on Collaborative Research
Fine-grained disclosure control for app ecosystems
Proceedings of the 2013 ACM SIGMOD International Conference on Management of Data
Hi-index | 0.00 |
We study the problem of finding efficient equivalent view-based rewritings of relational queries, focusing on query optimization using materialized views under the assumption that base relations cannot contain duplicate tuples. A lot of work in the literature addresses the problems of answering queries using views and query optimization. However, most of it proposes solutions for special cases, such as for conjunctive queries (CQs) or for aggregate queries only. In addition, most of it addresses the problems separately under set or bag-set semantics for query evaluation, and some of it proposes heuristics without formal proofs for completeness or soundness. In this paper we look at the two problems by considering CQ/A queries - that is, both pure conjunctive and aggregate queries, with aggregation functions SUM, COUNT, MIN, and MAX; the DISTINCT keyword in (SQL versions of) our queries is also allowed. We build on past work to provide algorithms that handle this general setting. This is possible because recent results on rewritings of CQ/A queries [1, 8] show that there are sound and complete algorithms based on containment tests of CQs.Our focus is that our algorithms are efficient as well as sound and complete. Besides the contribution we make in putting and addressing the problems in this general setting, we make two additional contributions for bag-set and set semantics. First, we propose efficient sound and complete tests for equivalence of CQ/A queries to rewritings that use overlapping views (the algorithms are complete with respect to the language of rewritings). These results apply not only to query optimization, but to all areas where the goal is to obtain efficient equivalent view-based query rewritings. Second, based on these results we propose two sound algorithms, BDPV and CDPV, that find efficient execution plans for CQ/A queries in terms of materialized views. Both algorithms extend the cost-based query-optimization approach of System R [19]. The efficient sound algorithm BDPV is also complete in some cases, whereas CDPV is sound and complete for all CQ/A queries we consider. We present a study of the completeness-efficiency tradeoff in the algorithms, and provide experimental results that show the viability of our approach and test the limits of query optimization using overlapping views.