Re: New statistics for tuning WAL buffer size

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: ikedamsh@oss.nttdata.com
Cc: masao.fujii@oss.nttdata.com, pgsql-hackers@postgresql.org, tsunakawa.takay@fujitsu.com, magnus@hagander.net
Date: 2020-09-11T03:17:16Z
Lists: pgsql-hackers
Hello.

At Wed, 09 Sep 2020 13:57:37 +0900, Masahiro Ikeda <ikedamsh@oss.nttdata.com> wrote in 
> I checked what function calls XLogBackgroundFlush() which calls
> AdvanceXLInsertBuffer() to increment m_wal_buffers_full.
> 
> I found that WalSndWaitForWal() calls it, so I added it.
> Is it better to move it in WalSndLoop() like the attached patch?

By the way, we are counting some wal-related numbers in
pgWalUsage.(bytes, records, fpi).  Since now that we are going to have
a new view related to WAL statistics, wouln't it be more useful to
show them together in the view?

(Another reason to propose this is that a substantially one-column
 table may look not-great..)

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center



Commits

  1. Add pg_stat_wal statistics view.