Re: Progress reporting for pg_verify_checksums

Hallo Michael,

> New patch attached.

Patch applies cleanly. Compiles, "make check" ok. doc build is also ok.

There are no tests, which is probably fine for such an interactive 
feature.

Docs look okay to me. Clear and to the point.

About :

  total_percent = total_size ? (int64) ((current_size / MEGABYTES) * 100 / (total_size / MEGABYTES)) : 0;

MEGABYTES can be simplified and will enhance precision. ISTM that the 
percent could be a double:

   total_percent = total_size ? 100.0 * current_size / total_size : 0.0 ;

and then just let fprintf do the rounding.

I would bother rounding down < 100% to 100, because then you would get

   1560/1492 MB (100\%, X MB/s)

which is kind of silly. If it goes over it just mean that the initial 
estimate was wrong, which might happen if the db is running (other patch 
in the queue). I'm fine with over 100 if it is consistent with the MB 
ratio next to it.

fprintf could be called once instead of twice by merging the eol and the 
previous message.

Maybe I'd consider inverting the sizeonly boolean so that more is done 
when true.

I'd still would use more precise than one second precision time so that 
the speed displayed at the beginning is more realistic. eg I got on a 
short test with probably in system cache files:

   188/188 MB (100%, 188 MB/s)

but the reality is that it took 0.126 seconds, and the speed was really 
1492 MB/s.

-- 
Fabien.