Abstract: A system for estimating cardinalities for a plurality of columns in a database system is disclosed. The system include obtaining statistics collected for the plurality of columns. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics. The system also include utilizing the first portion and the second portion of the statistics to estimate the cardinality for the plurality of columns.

Abstract: A method for processing database statements with join predicates on range-partitioned tables is provided. The method provides for receiving a database statement with a join predicate between a first table and a second table for processing, responsive to the join predicate involving one or more leading columns of a partition key for the first table, a nested-loop join operation being selected to join the first table and the second table, the first table being an outer table of the nested-loop join operation, and data from the second table being piped, calculating maximum and minimum join key values for the second table, creating a partition elimination bitmap for the first table based on the maximum and minimum join key values of the second table, and pushing the partition elimination bitmap onto a scan of the first table to exclude one or more partitions of the first table from the scan.

Abstract: In accordance with aspects of the present invention, provided are methods for incrementally estimating the cardinality of a derived relation including statistically correlated partially applicable predicates for a range-partitioned table. During the generation of a QEP a cardinality estimate is calculated in which one or more partially applicable predicates is correlated to another partially applicable predicate and/or to one or more fully applicable predicates. The cardinality includes a number of rows expected to be returned by the QEP and is computed in an incremental fashion for each operator of the QEP.

Abstract: A method and system for estimating cardinalities for a plurality of columns in a database system is disclosed. The method and system include obtaining statistics collected for the plurality of columns. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics. The method and system also include utilizing the first portion and the second portion of the statistics to estimate the cardinality for the plurality of columns.

Abstract: A system for estimating cardinalities for a plurality of columns in a database system is disclosed. The system include obtaining statistics collected for the plurality of columns. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics. The system also include utilizing the first portion and the second portion of the statistics to estimate the cardinality for the plurality of columns.

Abstract: In accordance with aspects of the present invention, provided are methods for incrementally estimating the cardinality of a derived relation including statistically correlated partially applicable predicates for a range-partitioned table. During the generation of a QEP a cardinality estimate is calculated in which one or more partially applicable predicates is correlated to another partially applicable predicate and/or to one or more fully applicable predicates. The cardinality includes a number of rows expected to be returned by the QEP and is computed in an incremental fashion for each operator of the QEP.

Abstract: In accordance with aspects of the present invention, provided are methods, systems, and computer program products for incrementally estimating the cardinality of a derived relation including statistically correlated partially applicable predicates for a range-partitioned table. During the generation of a QEP a cardinality estimate is calculated in which one or more partially applicable predicates is correlated to another partially applicable predicate and/or to one or more fully applicable predicates. The cardinality includes a number of rows expected to be returned by the QEP and is computed in an incremental fashion for each operator of the QEP.

Abstract: A method and system for estimating cardinalities for a plurality of columns in a database system is disclosed. The method and system include obtaining statistics collected for the plurality of columns. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics. The method and system also include utilizing the first portion and the second portion of the statistics to estimate the cardinality for the plurality of columns.