Incremental maintenance of materialized views containing one-to-N lossless joins
US6125360A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1998 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Jul 2, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99944
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for performing incremental refreshes to materialized views defined by one-to-N lossless joins. Each base table of the materialized view is selected to be processed as the current "selected table". The processing of the current selected table varies depending on whether the selected table is the right side table of an outer join. If the selected table is not the right table of an outer join, then the selected table is processed by (1) deleting rows from the materialized view based on rows of the selected table that have been updated or deleted in the selected table during the batch window, and (2) inserting rows into the materialized view based on updates and inserts into the selected table that occurred during the batch window. If the selected table is the right table of an outer join, then changes made to the selected table are processed in a way that reduces the number of changes that have to be made to the materialized view. According to one embodiment of the invention, operations performed during the incremental refresh are performed by issuing database statements (e.g. SQL queries) to a database server. The incremental refresh techniques des…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.