Cost-based query rewrite using materialized views
US7991765B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2008 |
| Grant date | Aug 2, 2011 |
| Priority date | — |
| Expiry date | Sep 15, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24542
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system and method of rewriting a database query where the query contains an aggregate includes the following. If one or more aggregate materialized views are considered, rewriting the query using an aggregate materialized view. If one or more non-aggregate multi-table materialized views are considered, the query is rewritten using a multi-table materialized view. A join cost is determined for each such non-aggregate multi-table materialized view. If one or more non-aggregate single table materialized views are considered, the query is rewritten using the single table materialized view. A join cost is determined for each such non-aggregate single table materialized view. Finally, a current total cost is determined for use of various materialized views as a function of join cost, aggregation cost and spool cost to select a rewritten query.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.