Processing in parallel units of work that perform DML operations on the same spanning rows
US6961729B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2001 |
| Grant date | Nov 1, 2005 |
| Priority date | — |
| Expiry date | Jun 10, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99944
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A mechanism is described for constructing work granules, where the work granules are constructed independently of whether two or more of the work granules are assigned to operate on a logical storage unit that contains a portion of the same row. A database system maintains transaction control data for data blocks in a manner that avoids self-deadlocks for slaves that follow a row collision protocol. A row collision protocol is a set of rules or steps that slaves follow to ensure that only one subtransaction in a distributed transaction updates a spanning row. Thus, for a particular spanning row, a single subtransaction modifies all the row pieces of the spanning row in any data block containing any row pieces of the spanning row. Consequently, a given data block may be affected by multiple subtransactions in a distributed transaction, one subtransaction affecting a row piece in the data block, another subtransaction affecting other rows in the data block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.