Dynamic partition enhanced inequality joining using a value-count index

Methods, computer programs, and database systems for performing a database query to join a column A and a column B on an inequality condition are disclosed. A database includes value-count indexes for columns A and B. Minimum and a maximum values for A and B are determined, using the value-count ind...

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Bibliographic Details
Main Authors MORRIS J. MARK, RAMESH BHASHYAM
Format Patent
LanguageEnglish
Published 18.01.2011
Subjects
CALCULATING
COMPUTING
COUNTING
ELECTRIC DIGITAL DATA PROCESSING
PHYSICS
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Summary:Methods, computer programs, and database systems for performing a database query to join a column A and a column B on an inequality condition are disclosed. A database includes value-count indexes for columns A and B. Minimum and a maximum values for A and B are determined, using the value-count indexes for A and B, respectively. The method includes defining three or more sets of values in A and B, relative to the minimum and maximum values for B and A, respectively. The method includes generating one or more Cartesian products between values in A and B. The database query is performed on a set of values in A and a set of values in B to generate a partial query result. The method includes merging one or more Cartesian products and the partial query result.
Bibliography:Application Number: US20040862649