Data processing: database and file management or data structures – Database design – Data structure types
Patent
1997-05-02
2000-10-24
Vonbuhr, Maria N.
Data processing: database and file management or data structures
Database design
Data structure types
G06F 1730
Patent
active
06138111&
ABSTRACT:
Method and apparatus for optimizing the processing of join queries based on join cardinality. Embodiments implement the methods in query optimizers in relational database management systems. A good join order for a multiple join query is found with a metric that compares the relative merits of candidate join orders as a whole. Embodiments estimate the join selectivity of foreign key--foreign key joins, where both participating tables are foreign keys with respect to a primary or unique key of one primary table. A graph representation of a query is processed to estimate the join cardinality of an arbitrarily large number of filters and joins, including any combination of primary key--foreign key joins and foreign key--foreign key joins.
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Informix Software, Inc.
Vonbuhr Maria N.
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