Re: Progress reporting for pg_verify_checksums

On Sat, Mar 30, 2019 at 06:52:56PM +0100, Fabien COELHO wrote:
> I do not think that it matters. I like to see things moving, and the
> performance impact is null.

Another point is that this bloats the logs redirected to a file by 4
compared to the initial proposal.  I am not sure that this helps
much for anybody.

> I do not think that it is a good idea, because Michael is thinking of adding
> some throttling capability, which would be a very good thing, but which will
> need something precise, so better use the precise stuff from the start.
> Also, the per second stuff induces rounding effects at the beginning.

Let's revisit that when the need shows up then.  I'd rather have us
start with a basic set of metrics which can be extended later on.

> Hmmm. I like this information because I this is where I have expectations,
> whereas I'm not sure whether 1234 seconds for 12.3 GB is good or bad, but I
> know that 10 MB/s on my SSD is not very good.

Well, with some progress generated once per second you are one
substraction away to guess how much has been computed in the last N
second...
--
Michael