Efficient join with one or more large dimension tables
US9141667B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2013 |
| Grant date | Sep 22, 2015 |
| Priority date | — |
| Expiry date | Aug 23, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2456
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Embodiments of the invention relate to processing queries that utilize fact and/or dimension tables. In one aspect, a pre-join filtering phase precedes a star join. The necessary conditions for the pre-join filtering are considered for a given SQL query, including an estimated size of the hash table exceeding a threshold and presence of a local predicate either on the fact table or one or more dimension tables that is not a large dimension table. Once the necessary conditions are satisfied, the execution of the query exploits the pre-join filtering to build a pre-join output filter from columns of a reduced fact table that joins with each large dimension table. Thereafter, all the dimension tables and the fact table are joined in a star join while exploiting each pre-join filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.