On Sun, Apr 6, 2025 at 10:15 PM Andres Freund <and...@anarazel.de> wrote: > > Hi, [..] > The obvious solution to that would be to increase BAS_BULKREAD substantially > above 256kB. > > For quite a while was worried about increasing the size, because somewhere (I > couldn't find it while writing this email, will add the reference once I > refound it) we have a comment explaining that a small size was chosen because > it helps with CPU cache efficiency.
Hi, FWIW, I was trying to understand the scope of this change and GetAccessStrategy() actually asks to go to src/backend/storage/buffer/README which explains the logic behind the old (pre-commit now) rationale and value. It says ``` For sequential scans, a 256KB ring is used. That's small enough to fit in L2 cache, which makes transferring pages from OS cache to shared buffer cache efficient. ``` -J.
