International Business Machines Corporation

Peter J Duffy

Pedro Miguel Barbas

David M Tilson

Lei Pan

In one embodiment, a method of processing a structured query language (SQL) statement is provided, comprising: determining whether a first query and a second query are equivalent, the first and second queries being respectively the left side and the right side operands of the OUTER JOIN operation; determining whether a SELECT output of the SQL statement does not refer to database columns from the left side of the OUTER JOIN operation which are not also partitioning columns of the OUTER JOIN operation; and responsive to determining that the first query and the second query are equivalent and that the SELECT output of the SQL statement does not refer to database columns from the left side of the OUTER JOIN operation which are not also partitioning columns of the OUTER JOIN operation, transforming the SQL statement into an optimized query SQL statement by removing the OUTER JOIN operation.

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Dublin, Ireland

Peter J Duffy