System and method for avoiding complete index tree traversals in sequential and almost sequential index probes
US5748952A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1995 |
| Grant date | May 5, 1998 |
| Priority date | — |
| Expiry date | May 10, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99953
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a system and method for utilizing the proximity of keys in sequential or near sequential index probes to avoid complete index tree traversal. Page information from three pages (LAST, PARENT and NEXT) are stored in separate information fields within an Index Lookaside Buffer. The LAST information field contains information on the most recent leaf page accessed during an index probe in a read key or an insert key operation, the PARENT information field contains information on the parent page of the most recently accessed leaf page described in the LAST information field, and the NEXT information field contains information on the most recent leaf page accessed during a fetch-next key or delete key operation. On a subsequent index probe, the LAST, NEXT and PARENT information fields are sequentially analyzed to determine if the search key is contained within the leaf page described by the LAST or NEXT information fields or if the search key is contained within one of the leaf pages pointed to by the parent page described by the PARENT information field. If none of the LAST, NEXT or PARENT information fields identify the leaf page containing the search key …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.