Providing the timing of the last committed change to a row in a database table
US7953749B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 2004 |
| Grant date | May 31, 2011 |
| Priority date | — |
| Expiry date | Sep 8, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2358
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Processing a database statement received from a database client, which requests information about the timing of a last committed change to a row in a database table, comprises retrieving a logical time value that represents a commit time associated with the row and providing the value to the client. In one embodiment, providing the logical time value to the client is enabled by database infrastructure in which a virtual column is used to temporarily “store” the value so that the value can be manipulated as if the value resided in a column of the row. Performance of operations that involve the virtual column are processed similar to real columns, as if data was actually logically stored in the virtual column. For example, the virtual column can be used in condition clauses of database statements for concurrency control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.