Techniques for exact cardinality query optimization
US8185519B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2009 |
| Grant date | May 22, 2012 |
| Priority date | — |
| Expiry date | Sep 24, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24542
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An exact cardinality query optimization system and method for optimizing a query having a plurality of expressions to obtain a cardinality-optimal query execution plan for the query. Embodiments of the system and method use various techniques to shorten the time necessary to obtain the cardinality-optimal query execution plan, which contains the query execution plan when all cardinalities are exact. Embodiments of the system and method include a covering queries technique that leverages query execution feedback to obtain an unordered subset of relevant expressions for the query, an early termination technique that bounds the cardinality to determine whether the processing can be terminate before each of the expressions are executed, and an expressions ordering technique that finds an ordering of expressions that yields the greatest reduction in time to obtain the cardinality-optimal query execution plan.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.