Outer join optimizations in database management systems
US10198472B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 2016 |
| Grant date | Feb 5, 2019 |
| Priority date | — |
| Expiry date | Mar 31, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24537
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.