System, method, and program for using direct and indirect pointers to logically related data and targets of indexes
US5933820A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1996 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | May 20, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99931
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The system, method, and program product of this invention allows a database management system to internally use direct and indirect pointing to locate targeted data elements that are logically related to another data element or are a target of a secondary index. By using direct and indirect pointing, the number of steps involved in a reorganization of the database can be reduced. After a reorganization, the database management system does not go back, in a separate process, to update all of the direct pointers that have pointed to segments that have moved as a result of the reorganization. Instead, the direct pointer is updated, by using the indirect pointer, only upon a first reference to the targeted data element that has moved. As such, each data element, that points to a targeted data element, has a direct pointer associated with it having a unique identifier of the targeted data element, assigned by the DBMS at the time a data element is created, a partition id of the targeted segment, a reorganization number, and a pointer to a location of the targeted data element. Each targeted data element has an entry in an indirect index where the unique identifier is the key into the in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.