Re: Query progress indication - an implementation - Mailing list pgsql-hackers

From Scara Maccai
Subject Re: Query progress indication - an implementation
Date
Msg-id 197024.3126.qm@web24613.mail.ird.yahoo.com
Whole thread Raw
In response to Query progress indication - an implementation  (Scara Maccai <m_lists@yahoo.it>)
List pgsql-hackers
> +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
availableonly 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'tgive them those results... 







pgsql-hackers by date:

Previous
From: Peter Eisentraut
Date:
Subject: 8.5 development schedule
Next
From: Jeremy Kerr
Date:
Subject: [PATCH 0/2 v3] SIGPIPE masking in local socket connections