Conference Schedule - PGCon 2022

Improving PostgreSQL's mysterious SLRU subsystem

Date: 2022-05-27
Time: 13:15–14:15
Room: Stream 2
Level: Intermediate

Alongside relation data (tables and indexes), PostgreSQL also manages 7 different sets of "SLRU" files. This talk will go into detail about the most important ones for transaction management. Topics will include:

  • Overview of the 7 SLRUs
  • The commit log's design and history
  • The multixact log's design and history
  • Why don't other databases have those things?
  • Access patterns
  • Format, I/O and buffering
  • How can we make all of this faster and more reliable?
  • Proposals to unify with the main buffer pool
  • Experimental results


Thomas Munro