Patent · US Active

Virtual pair algorithm for outer join resolution

US7941423B2 · kind B2 · utility

2Cited by

5References

20Claims

0Family size

Assignee

SAP AG · DE

Inventors

Gerhard Hill · St. Leon-Rot, DE
Thomas Peh · Bukit Mertajam, MY
Jane Hartmann · Bischofswerda, DE

Key dates

Filing date	Feb 19, 2010
Grant date	May 10, 2011
Priority date	—
Expiry date	Feb 19, 2030

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10S707/99932
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

A system and method for executing semijoin reductions on outer join operations are presented. Tuple lists are created based on a query. A sequence of semijoin reduction steps are performed, where each semijoin reduction step either switches one tuple list, or reduces all tuple lists at one relation. Virtual connector pairs are inserted into the tuple lists, and then all tuple lists are centralized at a common host. The join results are assembled at the common host, and negative row IDs are substituted. From the join result, the query result is retrieved by projecting to the requested attributes.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.