Re: Filesystem Direct I/O and WAL sync option

Yes Gregory, that's why I'm asking, because from 1800 transactions/sec
I'm jumping to 2800 transactions/sec! and it's more than important
performance level increase :))

Rgds,
-Dimitri

On 7/4/07, Gregory Stark <stark(at)enterprisedb(dot)com> wrote:
>
> "Dimitri" <dimitrik(dot)fr(at)gmail(dot)com> writes:
>
> > Yes, disk drives are also having cache disabled or having cache on
> > controllers and battery protected (in case of more high-level
> > storage) - but is it enough to expect data consistency?... (I was
> > surprised about checkpoint sync, but does it always calls write()
> > anyway? because in this way it should work without fsync)...
>
> Well if everything is mounted in sync mode then I suppose you have the same
> guarantee as if fsync were called after every single write. If that's true
> then surely that's at least as good. I'm curious how it performs though.
>
> Actually it seems like in that configuration fsync should be basically
> zero-cost. In other words, you should be able to leave fsync=on and get the
> same performance (whatever that is) and not have to worry about any risks.
>
> --
> Gregory Stark
> EnterpriseDB http://www.enterprisedb.com
>
>