Flexible query hints in a relational database
US8190595B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2009 |
| Grant date | May 29, 2012 |
| Priority date | — |
| Expiry date | Aug 17, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A flexible query hints system and method for discovering and expressing query hints in a database management system. Embodiments of the flexible query hints system and method include a power hints (Phints) language that enables the specification of constraints to influence a query optimizer. Phints expressions are defined as tree patterns annotated with constraints. Embodiments of the flexible query hints system and method also include techniques to incorporate the power hints language expressions into an extended query optimizer. Theses techniques include computing a directed acyclic graph for Phints expression, deriving candidate matches using the Phints expression and the graph, computing candidate matches, and extracting a revised execution plan having a lowest cost and satisfying constraints of the Phints expression. Embodiments of the flexible query hints system and method include a flexible query hint user interface that allow users to interactively adjust query hints.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.