GROUP-BY AND DISTINCT PUSHDOWN INTO UNION-ALL VIEWS

A mechanism is provided for performing a group-by pushdown operation or a distinct pushdown operation on a query. The query comprises an outer query block containing a view with a union-all operator, and the outer query block comprises an outer query statement referencing one or more columns of the...

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Bibliographische Detailangaben
Hauptverfasser: AHMED, RAFI, WITKOWSKI, ANDREW
Format: Patent
Sprache:eng
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Beschreibung
Zusammenfassung:A mechanism is provided for performing a group-by pushdown operation or a distinct pushdown operation on a query. The query comprises an outer query block containing a view with a union-all operator, and the outer query block comprises an outer query statement referencing one or more columns of the union-all view and a group-by statement or a distinct keyword. Performing the group-by pushdown operation or the distinct pushdown operation on the query comprises modifying at least a given branch of the union-all view to include a distinct keyword in a query statement of the given branch or a group-by clause that groups results of the given branch by the one or more columns of the table of the given branch.