Tom Lane <t...@sss.pgh.pa.us> writes: > "Robert Haas" <robertmh...@gmail.com> writes: >> OK, here's an update of Greg's patch with the runtime configure test >> ripped out, some minor documentation tweaks, and a few unnecessary >> whitespace diff hunks quashed. I think this is about ready for >> committer review. > > I've applied most of this, with a couple of notable revisions: > > 1. The runtime check on whether posix_fadvise works is really gone. > We'll see whether we need to put anything back, but I think our first > try should be under the assumption that it works. (BTW, I was wrong > in my earlier claim that the buildfarm wouldn't exercise posix_fadvise > by default --- the patch defaults to io_concurrency = 1 if fadvise > is available, so it will try to prefetch one page ahead.) > > 2. I fixed it so that setting effective_io_concurrency to zero disables > prefetching altogether; there was no way to do that in the patch as > submitted.
Hm. the original intent was that effective_io_concurrency 1 meant no prefetching because there was only one drive. I wonder if that worked earlier and got lost along the way or if I always had this wrong. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's 24x7 Postgres support! -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
