Hi Moreno:
On Wed, Aug 3, 2016 at 1:07 PM, Moreno Andreo <moreno.andreo@evolu-s.it> wrote:
It's already been answered, but as it seems to be answering a chunk of
my mail...
> Should I keep fsync off? I'd think it would be better leaving it on, right?
Yes. If you have to ask wether fsync should be on, it should.
I mean, you only take it off when you are absolutely sure of where you
are doing, fsync off goes against the D in acid.
You normally only turn it off in counted cases. As an example we have
an special postgresql.conf for full cluster restores, with fsync=off.
Wehen we need it we stop the cluster, boot it with that, restore, stop
it again and reboot with the normal fsync=on config. In this case we
do not mind losing data as we are doing a full restore anyway.
But normally, its a bad idea. As a classic photo caption says,
fsync=off => DBAs running with scissors.
Francisco Olarte.