SQL execution plan verification
US8700608B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2008 |
| Grant date | Apr 15, 2014 |
| Priority date | — |
| Expiry date | Sep 6, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24542
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Approaches, techniques, and mechanisms are disclosed for ensuring that a database command is executed according to a query plan that has been verified to be actually optimal. Except in rare circumstances, a database server does not execute a query plan unless it is first verified by the database server. The database server receives a request to execute a database command. The database server determines an unverified plan is the best plan for satisfying the request. Rather than risk the unknown behavior of an unverified plan, the database server instead satisfies the request according to a verified plan. Subsequently—for example as part of a scheduled job—the database server executes the unverified plan to determine performance statistics. Based at least on the performance statistics, the database server determines whether or not to verify the unverified plan. Techniques for concurrent and optimistic verifications are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.