From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Geoghegan <pg@heroku.com>
Cc: 大塚憲司 <otsuka.kenji@nttcom.co.jp>
Cc: pgsql-docs@postgresql.org, Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] The number of bytes is stored in index_size of pgstatindex() ?
Date: Thu, 18 Feb 2016 13:01:10 -0500
Message-ID: <377.1455818470@sss.pgh.pa.us> (raw)
In-Reply-To: <CAM3SWZQtQ2WDGRqa2g_dbfHuu9CebfWvJ_XpXggFoFG1mUYzXw@mail.gmail.com>
References: <56C5B2C7.7010604@nttcom.co.jp>
<31925.1455817248@sss.pgh.pa.us>
<CAM3SWZQtQ2WDGRqa2g_dbfHuu9CebfWvJ_XpXggFoFG1mUYzXw@mail.gmail.com>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-docs>
Peter Geoghegan <pg@heroku.com> writes:
> On Thu, Feb 18, 2016 at 9:40 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I think this is a bug and we ought to fix the code to include the
>> metapage in the reported index_size. Thoughts?
> I tend to agree, but I think you should note that specifically in the
> documentation. I'm in favor of tools like pgstattuple and pageinspect
> going into this kind of detail in their documentation generally.
Yeah ... the numbers already appear not to add up because the root page
is counted in index_size but not any other column, so there's already
something worthy of explanation there. Maybe something like "The reported
index_size will normally correspond to two more pages than are accounted
for by internal_pages + leaf_pages + empty_pages + deleted_pages, because
it also includes the index's metapage and root page".
regards, tom lane
--
Sent via pgsql-docs mailing list (pgsql-docs@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-docs
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-docs@postgresql.org
Cc: tgl@sss.pgh.pa.us, pg@heroku.com, otsuka.kenji@nttcom.co.jp, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] The number of bytes is stored in index_size of pgstatindex() ?
In-Reply-To: <377.1455818470@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox