Alvaro Herrera wrote: > There was no discussion whatsoever of the "prefetch" patch in this > thread; and as far as I can see, nobody even mentioned such an idea in > the thread. This prefetch patch appeared out of the blue and there was > no discussion about it that I can see. Now I was about to push it after > some minor tweaks, and went to search where was its justification, only > to see that there was none. Did anybody run tests with this patch? > > I attach it now one more time. My version is based on the latest > Claudio posted at > https://postgr.es/m/CAGTBQpa464RugxYwxLTtDi=syv9gngfcjk8uzb2fr6nddqu...@mail.gmail.com > I don't know if there are differences to the version first posted. > I only changed the magic number 32 to a #define, and added a > CHECK_FOR_INTERRUPTS in the prefetching loop.
Ah, I found the justification here: https://www.postgresql.org/message-id/flat/CAGTBQpa464RugxYwxLTtDi%3DSyv9GnGFcJK8uZb2fR6NDDqULaw%40mail.gmail.com#CAGTBQpbayY-t5-ySW19yQs1dBqvV6dm8dmdpTv_FWXmDC0A0cQ%40mail.gmail.com apparently the truncate scan is 4x-6x faster with this prefetching. Nice! -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
