Database management system, and query method and query execution program in the database management system
US6925462B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2002 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Feb 4, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99933
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an optimization method in a database management system having the function of accessing external databases. Conventionally, whether functions contained in a query can be executed in external databases depends on a database management system having the functions, and therefore there has been a problem in that a database utilization method cannot apply to query optimization and query execution performance is reduced. To solve the above problem, a database management system having the function of accessing external databases is provided with an optimization step comprising the steps of: obtaining specification about whether to execute functions in a query in external databases; determining whether data referred to in a query is confined to one database; and determining whether a user specifies that the functions in the query are executed in external databases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.