Date: 2026-05-20
Time: 13:00–13:50
Room: Labatt
Level: Intermediate
Postgres supports AIO since version 18, and a most of the basic executor nodes were already modified to leverage this capability. In many cases this results in significant performance improvements, particularly on storage that requires prefetching.
Index scans are one of the remaining pieces that still don't leverage AIO, despite the obvious benefits of prefetching with random I/O.
In this talk we will discuss the work we've done on using AIO for index scans - the current state of the work, what were (are) the main challenges and difficulties of this multi-year project. We'll explain the basic concepts introduced by the patches (batching, additions to index AM interface, ...) and how it all works together. We'll also share some numbers on performance.