Efficient garbage collection in optimistic multi-writer database systems
US11874796B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 2019 |
| Grant date | Jan 16, 2024 |
| Priority date | — |
| Expiry date | Feb 17, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2365
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Systems and methods are disclosed to implement, in a multi-writer database system, a database engine node that optimistically sends queued purge operations to a backend storage system without waiting for acknowledgement of previous operations from the storage system. If a conflict is later detected for a particular operation, the database engine node may retry some portion of the purge operations in the queue. In embodiments, the purge operations are performed as part of a garbage collection phase of a multi-version concurrency control (MVCC) protocol, where unneeded versions of objects previously generated for isolated snapshots are deleted. In embodiments, the operations in the queue may be grouped so that a rejection of one operation in the group will cause the entire group to be retried. Because these purge operations are idempotent and directed to objects that are invisible, they may be freely retried in arbitrary order, without maintaining any rollback state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.