Conference Schedule - PGConf.EU 2019

Instantaneous transaction rollback, and other advantages of versioned storage

Date: 2019-10-17
Time: 11:50 - 12:40
Room: Manzoni
Level: Intermediate

PostgreSQL's approach to MVCC is based on versioned storage, and owes much to the time travel feature that appeared in the original Berkeley codebase. An asynchronous cleanup process (VACUUM) garbage collects obsolete row versions, with additional cleanup performed by user transactions opportunistically. This approach has significant differences to the approaches taken by other database systems, which generally either support two-phase locking, a limited form of MVCC with remnants of two-phase locking, or both.

The use of versioned storage is not purely an accident of history; it's a design trade-off with non-obvious practical advantages and disadvantages for DBAs and application developers. This talk will focus on the advantages.

Topics covered include:


Peter Geoghegan