On 2019-Nov-22, Antonin Houska wrote: > I thought that in [1] you try discourage me from using pg_pread(), but now it > seems to be the opposite. Ideally I'd like to see no overhead added by my > patch at all, but the code simplicity should matter too.
FWIW I think the new code is buggy because it doesn't seem to be setting ws_off, so I suppose the optimization in ReadPageInternal to skip reading the page when it's already the page we have is not hit, except for the first page in the segment. I didn't verify this, just my impression while reading the code. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
