Method and system for outer join of database tables
US10885035B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 18, 2020 |
| Grant date | Jan 5, 2021 |
| Priority date | — |
| Expiry date | May 18, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2456
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The specification provides a system, method, and storage medium for executing an outer join command on a first table and a second table in a distributed database. The method may comprise: broadcasting the first table to a plurality of second nodes storing the second table; selecting one or more second nodes from the plurality of second nodes; obtaining, by each of the selected one or more second nodes, an outer join result after executing an outer join operation; obtaining, by each of the plurality of second nodes other than the selected one or more second nodes, an inner join result; removing a row with (1) a join key value and (2) a NULL value from the outer join result when the inner join result comprises another row with the join key; and returning, after the removal, a result to the outer join command by aggregating the outer join result and the inner join result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.