Avoiding lock contention by using a wait for completion mechanism
US7644106B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2007 |
| Grant date | Jan 5, 2010 |
| Priority date | — |
| Expiry date | Apr 26, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99952
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques for avoiding lock contention when processing data definition language (DDL) statements are provided. Some DDL statements modify metadata of a table and then require access to the table. After such a DDL statement modifies the metadata of a table and the updated metadata is made available (i.e., published) to other database statements, execution of the DDL statement is suspended. Data manipulation language (DML) statements acquire locks on the table. In one approach, the locks, of any DML statement, that are granted after the DDL statement is issued are timestamped. The DDL statement uses the timestamps to determine when to access the table. The timestamps are used to determine when the last DML statement (that was pending at the time the modified metadata was published) commits and releases its lock on the table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.