Query optimization by simulated annealing
SIGMOD '87 Proceedings of the 1987 ACM SIGMOD international conference on Management of data
Optimization of large join queries
SIGMOD '88 Proceedings of the 1988 ACM SIGMOD international conference on Management of data
Optimization of large join queries: combining heuristics and combinatorial techniques
SIGMOD '89 Proceedings of the 1989 ACM SIGMOD international conference on Management of data
Practical selectivity estimation through adaptive sampling
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
Randomized algorithms for optimizing large join queries
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
SIGMOD '91 Proceedings of the 1991 ACM SIGMOD international conference on Management of data
Optimization of object-oriented recursive queries using cost-controlled strategies
SIGMOD '92 Proceedings of the 1992 ACM SIGMOD international conference on Management of data
Statistical estimators for relational algebra expressions
Proceedings of the seventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Principles of Database Systems
Principles of Database Systems
Access path selection in a relational database management system
SIGMOD '79 Proceedings of the 1979 ACM SIGMOD international conference on Management of data
Accurate estimation of the number of tuples satisfying a condition
SIGMOD '84 Proceedings of the 1984 ACM SIGMOD international conference on Management of data
Optimization of Nonrecursive Queries
VLDB '86 Proceedings of the 12th International Conference on Very Large Data Bases
VLDB '88 Proceedings of the 14th International Conference on Very Large Data Bases
LEO - DB2's LEarning Optimizer
Proceedings of the 27th International Conference on Very Large Data Bases
Robust query processing through progressive optimization
SIGMOD '04 Proceedings of the 2004 ACM SIGMOD international conference on Management of data
LEO: An autonomic query optimizer for DB2
IBM Systems Journal
Consistently estimating the selectivity of conjuncts of predicates
VLDB '05 Proceedings of the 31st international conference on Very large data bases
Consistent selectivity estimation via maximum entropy
The VLDB Journal — The International Journal on Very Large Data Bases
Progressive query optimization for federated queries
EDBT'06 Proceedings of the 10th international conference on Advances in Database Technology
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A model is described to estimate the size of intermediate relations produced by large relational algebra expressions, in particular, those containing several equi-joins. The intended application is within query optimization searches, where fast estimates are needed as many alternative plans are examined. It is shown that previous methods, which use an independence assumption when several attributes are joined, can lead to unrealistically low size estimates. This method attempts to overcome that problem by the introduction of “virtual domains”, which avoid the independence assumption. The method does not require extensive statistics about the database. After describing an “exact” version, an approximation that is simpler and faster is presented.