Hi, On 2020-12-04 13:27:38 -0500, Stephen Frost wrote: > If I follow correctly, this patch will scan ahead in the WAL and let > the kernel know that certain blocks will be needed soon. Ideally, > though I don't think it does yet, we'd only do that for blocks that > aren't already in shared buffers, and only for non-FPIs (even better if > we can skip past pages for which we already, recently, passed an FPI).
The patch uses PrefetchSharedBuffer(), which only initiates a prefetch if the page isn't already in s_b. And once we have AIO, it can actually initiate IO into s_b at that point, rather than fetching it just into the kernel page cache. Greetings, Andres Freund
