Re: [9.4] Make full_page_writes only settable on server start?

On Sep 3, 2013 6:23 PM, "Josh Berkus" <josh(at)agliodbs(dot)com> wrote:
>
> Peter,
>
>
> > I wonder, is anyone really running in production with full_page_writes
> > off?
>
> We're doing so with clients on Joyent (ZFS). And also for "ephemeral"
> postgres instances -- ones where we've also turned off fsync.
>
> It's also quite reasonable to assume that future filesystems will also
> be able to make better torn page guarantees.
>
> So it should remain a setting. I see no reason why it should be a
> SIGHUP setting, though, if there's any code maintenance required to
> support it -- frankly, I only change this setting at first system
> deployment.
>

This matches my experience as well - people certainly use it, but don't
change it during runtime.

Not having looked at the code, but doesn't pg_start_backup use at least
parts of the same code path? That one will definitely still be able to
modify it at runtime....

/Magnus