Re: Query progress indication - an implementation

> +1.  Especially if I run it a few times and I can see
> which counters
> are still moving.

Per-node percentage is easy to do (given the perfect estimates, of course).
The problem comes when you want to give an "overall" percentage.

I wouldn't know where to put that "explain-like" output though: in a column in pg_stat_get_activity??? (and it would be available only if the proper variable was "on" before sending the query)

> -1.    A counter that slowly goes from 99% to
> 99.5% done is
> much worse than a counter that takes the same much time
> going from "1000% of estimated rows done" to "2000% of
> estimated rows done".

It's not just about estimates.
Even with 100% correct estimates, IMHO there's no way to get the perfect amount of work done so far.
And this is even without considering multiple queries running at the same time...

If someone has some time to read those papers let me know what he thinks about them... because I think their methods couldn't give them those results...