ACM Transactions on Database Systems (TODS)
Estimating the size of generalized transitive closures
VLDB '89 Proceedings of the 15th international conference on Very large data bases
Optimal histograms for limiting worst-case error propagation in the size of join results
ACM Transactions on Database Systems (TODS)
Adaptive query optimization in a deductive database system
CIKM '93 Proceedings of the second international conference on Information and knowledge management
Adaptive selectivity estimation using query feedback
SIGMOD '94 Proceedings of the 1994 ACM SIGMOD international conference on Management of data
Query size estimation by adaptive sampling
Selected papers of the 9th annual ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Advanced database systems
Size-estimation framework with applications to transitive closure and reachability
Journal of Computer and System Sciences
Efficient mid-query re-optimization of sub-optimal query execution plans
SIGMOD '98 Proceedings of the 1998 ACM SIGMOD international conference on Management of data
Efficient and extensible algorithms for multi query optimization
SIGMOD '00 Proceedings of the 2000 ACM SIGMOD international conference on Management of data
Pipelining in multi-query optimization
PODS '01 Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
An infrastructure for adaptive dynamic optimization
Proceedings of the international symposium on Code generation and optimization: feedback-directed and runtime optimization
Robust query processing through progressive optimization
SIGMOD '04 Proceedings of the 2004 ACM SIGMOD international conference on Management of data
Proceedings of the 2005 ACM SIGMOD international conference on Management of data
Optimizing recursive queries in SQL
Proceedings of the 2005 ACM SIGMOD international conference on Management of data
Efficient implementation of recursive queries in major object relational mapping systems
FGIT'11 Proceedings of the Third international conference on Future Generation Information Technology
Adaptive optimizations of recursive queries in teradata
SIGMOD '12 Proceedings of the 2012 ACM SIGMOD International Conference on Management of Data
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Relational implementation of recursive queries is part of the ANSI SQL99 and was implemented in Teradata V2R6. Recursive queries allow processing of hierarchical data like air flight schedules, bill-of-materials, data cube dimension hierarchies, and ancestor-descendant information (e.g. XML data stored in relations). The initial Teradata recursive query implementation is based on a static (fixed) execution plan for all recursive iterations. This may not be optimal since the intermediate results from recursive iterations vary in size. To address this problem, this paper proposes dynamic re-optimization techniques to produce execution plans that are optimal for all recursive iterations. The approach employs a mix of multi-iteration pre-planning and dynamic feedback techniques that are generally applicable to any recursive query implementation in an RDBMS. We validate our proposed techniques by conducting experiments on a prototype implementation using airline flights data.