Re: Avoiding Recheck Cond when using Select Distinct

On Mon, Feb 25, 2013 at 10:11 AM, Maciek Sakrejda <m(dot)sakrejda(at)gmail(dot)com>wrote:

> On Sat, Feb 23, 2013 at 3:53 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
> > It would really help to have "explain (analyze, buffers)". Especially if
> > you turn on track_io_timing, (although that part probably can't be done
> on
> > Heroku, as it requires superuser access.)
>
> Right, that's not supported right now, although given that the
> superuser is primarily for performance considerations (right?),
> perhaps we should find some way of exposing this.
>

I don't think it is SUSET for performance reasons, as the ordinary user
already has plenty of ways to shoot themselves (and fellow users) in the
foot performance-wise. I think it was based on the idea that those
tracking tools that the administrator has turned on, ordinary users may
turn off. I think the other way around would be fine (if it is off for the
server, the user can still turn it on for their session--and presumably
also turn it off again if it is one only because they set it that way, not
because the administrator set it that way), but I think that that behavior
is not trivial to implement. I looked in the archives, but the SUSET
nature of this doesn't seem to have been discussed.

Cheers,

Jeff