From: lchch1990@sina.cn <lchch1990@sina.cn>
To: Masahiro Ikeda <ikedamsh@oss.nttdata.com>
To: 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: Wed, 21 Oct 2020 14:54:48 +0800
Message-ID: <2020102114544806663477@sina.cn> (raw)
References: <35ef960128b90bfae3b3fdf60a3a860f@oss.nttdata.com>
<CAA4eK1JbbP-QmZWiXwK+H-ZauJCGR6vbAVoGdyx_TTxRPuXzhQ@mail.gmail.com>
<06bc2d405b086a72fb14657de9befae8@oss.nttdata.com>
I think it's really a more convenient way to collect wal usage information,
with it we can query when I want. Several points on my side:
1. It will be nice If you provide a chance to reset the information in WalStats,
so that we can reset it without restart the database.
2. I think 'wal_write_backend' is mean wal write times happen in
backends. The describe in document is not so clear, suggest rewrite it.
3. I do not think it's a correct describe in document for 'wal_buffers_full'.
4. Quite strange to collect twice in XLogInsertRecord() for xl_tot_len,
m_wal_records, m_wal_fpi.
5. I notice some code in issue_xlog_fsync() function to collect sync info,
a standby may call the issue_xlog_fsync() too, which do not want to
to collect this info. I think this need some change avoid run by standby
side.
Regards,
Highgo Software (Canada/China/Pakistan)
URL : www.highgo.ca
EMAIL: mailto:movead(dot)li(at)highgo(dot)ca
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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: <2020102114544806663477@sina.cn>
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