On Sat, 2021-07-24 at 18:27 +0100, Matthew Wilcox wrote: > What blows me away is the 80% performance improvement for PostgreSQL. > I know they use the page cache extensively, so it's plausibly real. > I'm a bit surprised that it has such good locality, and the size of > the win far exceeds my expectations. We should probably dive into it > and figure out exactly what's going on. Since none of the other tested databases showed more than a 3% improvement, this looks like an anomalous result specific to something in postgres ... although the next biggest db: mariadb wasn't part of the tests so I'm not sure that's definitive. Perhaps the next step should be to test mariadb? Since they're fairly similar in domain (both full SQL) if mariadb shows this type of improvement, you can safely assume it's something in the way SQL databases handle paging and if it doesn't, it's likely fixing a postgres inefficiency. James
