Date: Mon, 5 Jun 2017 01:43:37 -0700
From: Andres Freund <andres@anarazel.de>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: pgsql-bugs@postgresql.org, chjischj@163.com
Subject: Re: BUG #14687: pg_xlogdump does only count "main data" for
 record length and leading to incorrect statistics
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On 2017-06-05 11:23:43 +0300, Heikki Linnakangas wrote:
> On 06/05/2017 05:25 AM, Andres Freund wrote:
> > Hi Heikki,
> > Do you see any better way to get at the !fpi len than to iterate over
> > the blocks and sum up the image length?  It's not really accurate to
> > display len (rec/tot) as total-fpi, total, but I don't have a better
> > backward-compatible idea?  Actually, I don't even have a better idea for
> > master, so maybe it's ok as proposed?
> 
> Your patch seems OK to me. Defining non-FPI size as (total_len - fpi_len)
> seems correct to me, I'm not sure what other definition you could have.

I'm not sure, that's why I chose the above.  But you could argue that
the block ids etc. shouldn't be counted as part of either, or that the
previous displaying of record len / total len doesn't make much sense
anymore.

Greetings,

Andres Freund


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