Re: Progress reporting for pg_verify_checksums

From: Michael Paquier <michael(at)paquier(dot)xyz>
To: Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
Cc: Michael Banck <michael(dot)banck(at)credativ(dot)de>, Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>, alvherre(at)2ndquadrant(dot)com, mailings(at)oopsware(dot)de, thomas(dot)munro(at)enterprisedb(dot)com, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Progress reporting for pg_verify_checksums
Date: 2019-03-30 14:31:09
Message-ID: 20190330143109.GC28827@paquier.xyz
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On Thu, Mar 28, 2019 at 03:53:59PM +0100, Fabien COELHO wrote:
> I think that it is good to show the overall impact of the signal stuff, in
> particular the fact that the size must always be computed if the progress
> may be activated.

Getting to know the total size and the current size are the two
important factors that matter when it comes to do progress reporting
in my opinion. I have read the patch, and I am not really convinced
by the need to show the progress report based on an interval of 250ms
as we talk about an operation which could take dozens of minutes. So
I have simplified the patch to only show a progress report every
second. This also removes the include for the time-related APIs from
portability/. A second thing is that I don't think that the speed is
much useful. I would expect the speed to be steady, still there is a
risk to show incorrect information if the speed of the operation is
spiky or irregular leading to an incorrect estimation of the remaining
time.

In short, I would like to commit the first patch as attached, which is
much more simple than what has been sent previously, still it provides
the progress information which is useful.
--
Michael

Attachment Content-Type Size
checksums-progress-report.patch text/x-diff 7.2 KB

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