On Tuesday 29 December 2009 11:48:10 Greg Stark wrote:
> On Tue, Dec 29, 2009 at 2:05 AM, Andres Freund <andres@anarazel.de> wrote:
> > Reads Completed: 2, 8KiB Writes Completed: 2362,
> > 29672KiB New:
> > Reads Completed: 0, 0KiB Writes Completed: 550,
> > 5960KiB
>
> It looks like the new method is only doing 1/6th as much i/o. Do you
> know what's going on there?
While I was surprised by the amount of difference I am not surprised at all
that there is a significant one - currently the fsync will write out a whole
bunch of useless stuff every time its called (all metadata, directory structure
and so on)
This is reproducible...
6MB sounds sensible for the operation btw - the template database is around
5MB.
Will try to analyze later what exactly causes the additional io.
Andres
