Adaptive filter index for determining queries affected by a DML operation
US8185508B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2008 |
| Grant date | May 22, 2012 |
| Priority date | — |
| Expiry date | Nov 28, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24565
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are disclosed for creating and using a filter index in order to identify registered queries whose result sets are likely to have been changed by changes made to tables. The filter index entries are based on filter conditions. The filter conditions are created based on predicates contained in the registered queries. The filter conditions may include exclusive predicates and join predicates. Join predicates that join a table T1 with a table T2 may be instantiated by replacing references to table T2 with values extracted from table T2. Various techniques are described for recognizing situations in which a query can be included in, or excluded from, the set of likely-changed queries, without fully evaluating the filter conditions that correspond to the queries.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.