On Wed, Feb 3, 2010 at 6:53 AM, Greg Stark <gsstark@xxxxxxx> wrote: > On Tue, Feb 2, 2010 at 7:45 PM, Robert Haas <robertmhaas@xxxxxxxxx> wrote: >> I think you're probably right, but it's not clear what the new name >> should be until we have a comment explaining what the function is >> responsible for. > > So I wrote some comments but wasn't going to repost the patch with the > unchanged name without explanation... But I think you're right though > I was looking at it the other way around. I want to have an API for a > two-stage sync and of course if I do that I'll comment it to explain > that clearly. > > The gist of the comments was that the function is preparing to fsync > to initiate the i/o early and allow the later fsync to fast -- but > also at the same time have the beneficial side-effect of avoiding > cache poisoning. It's not clear that the two are necessarily linked > though. Perhaps we need two separate apis, though it'll be hard to > keep them separate on all platforms. Well, maybe we should start with a discussion of what kernel calls you're aware of on different platforms and then we could try to put an API around it. I mean, right now all you've got is POSIX_FADV_DONTNEED, so given just that I feel like the API could simply be pg_dontneed() or something. It's hard to design a general framework based on one example. ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
