From: lchch1990@sina.cn <lchch1990@sina.cn>
To: Masahiro Ikeda <ikedamsh@oss.nttdata.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Add statistics to pg_stat_wal view for wal related parameter tuning
Date: Fri, 13 Nov 2020 11:32:23 +0800
Message-ID: <2020111311322320943423@sina.cn> (raw)
References: <35ef960128b90bfae3b3fdf60a3a860f@oss.nttdata.com>
<CAA4eK1JbbP-QmZWiXwK+H-ZauJCGR6vbAVoGdyx_TTxRPuXzhQ@mail.gmail.com>
<06bc2d405b086a72fb14657de9befae8@oss.nttdata.com>
<2020102114544806663477@sina.cn>
<ac8b1f5e589932254efe373e252e5dcb@oss.nttdata.com>
>Now, pg_stat_wal supports reset all informantion in WalStats
>using pg_stat_reset_shared('wal') function.
>Isn't it enough?
Yes it ok, sorry I miss this infomation.
>> 3. I do not think it's a correct describe in document for
>> 'wal_buffers_full'.
>Where should I rewrite the description? If my understanding is not
>correct, please let me know.
Sorry I have not described it clearly, because I can not understand the meaning of this
column after I read the describe in document.
And now I read the source code of walwrite and found the place where 'wal_buffers_full'
added is for a backend to wait a wal buffer which is occupied by other wal page, so the
backend flush the old page in the wal buffer(after wait it can).
So i think the origin decribe in document is not so in point, we can describe it such as
'Total number of times WAL data written to the disk because a backend yelled a wal buffer
for an advanced wal page.
Sorry if my understand is wrong.
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-hackers@postgresql.org
Cc: lchch1990@sina.cn, ikedamsh@oss.nttdata.com, amit.kapila16@gmail.com
Subject: Re: Add statistics to pg_stat_wal view for wal related parameter tuning
In-Reply-To: <2020111311322320943423@sina.cn>
* 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