4 ms·

for other fun low-level High Sierra issues, see the PostgreSQL msync() thread: https://www.postgresql.org/message-id/flat/13746.1506974083%40sss.pgh.pa.us#13746

• salarycommenter 9y ago
  Interesting. Mapping 64k at a time seems a bit excessive. If I call mmap it's to map everything I'm going to need, but maybe I am missing context.
  • snuxoll 9y ago
    PostgreSQL still supports 32-bit platforms, heap and index files can get large enough that it's not feasible to mmap them into a 32-bit process. As far as the specific number of 64k though, I don't know why they choose that, writing 8 pages to disk at a time (especially sequentially) doesn't really take advantage of modern hardware well.