Horton

Re: wal stats questions

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: ikedamsh@oss.nttdata.com, pgsql-hackers@postgresql.org, masao.fujii@oss.nttdata.com
Date: 2021-03-26T17:07:45Z
Lists: pgsql-hackers 
Hi,

On 2021-03-25 16:37:10 +0900, Kyotaro Horiguchi wrote:
> On the other hand, the counters are incremented in XLogInsertRecord()
> and I think we don't want add instructions there.

I don't really buy this. Setting a boolean to true, in a cacheline
you're already touching, isn't that much compared to all the other stuff
in there. The branch to check if wal stats timing etc is enabled is much
more expensive.  I think we should just set a boolean to true and leave
it at that.

Greetings,

Andres Freund

Commits

  1. Fix issues in pg_stat_wal.

  2. Change data type of counters in BufferUsage and WalUsage from long to int64.