Re: Why does analyze_new_cluster.sh use sleep?

On Thu, 2012-08-23 at 17:05 -0400, Bruce Momjian wrote:
> On Thu, Aug 23, 2012 at 02:17:44AM -0400, Peter Eisentraut wrote:
> > The script analyze_new_cluster.sh output by pg_upgrade contains several
> > "sleep" calls (see contrib/pg_upgrade/check.c). What is the point of
> > this? If the purpose of this script is to get the database operational
> > again as soon as possible, waiting a few seconds doing nothing surely
> > isn't helping.
> >
> > I could maybe see the point of waiting a bit between the different
> > vacuumdb calls, to catch some breath, but the one before the first call
> > to vacuumdb is highly dubious to me.
>
> The sleep is there so the user can read the status message, in case it
> scrolls off the screen once the next stage starts.

That seems completely arbitrary and contrary to the point of the script.
The pg_upgrade output already explains what the script is for. If we
really wanted the user to confirm what is going to happen, we should
wait for a key press or something. I also don't think that 2 seconds is
enough to read and react to the written text. Also, by that logic, we
need to put a delay between each database processed by vacuumdb as well.