Neil Conway wrote:
>The present Linux implementation doesn't do this, AFAICS -- all it does
>it increase the readahead for this file:
>
>
AFAIK Linux uses a modified LRU that automatically puts pages that were
touched only once at a lower priority than frequently accessed pages.
Neil: what about calling posix_fadvise for the whole file immediately
after issue_xlog_fsync() in XLogWrite? According to the comment, it's
guaranteed that this will happen only once.
Or: add an posix_fadvise into issue_xlog_fsync(), for the range just
sync'ed.
Btw, how much xlog traffic does a busy postgres site generate?
-- Manfred