Date: Tue, 30 Jun 2020 11:24:08 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Nikhil Shetty <nikhil.dba04@gmail.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Recommended value for pg_test_fsync
Message-ID: <20200630152408.GA28711@momjian.us>
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On Tue, Jun 30, 2020 at 10:32:13AM +0530, Nikhil Shetty wrote:
> Hi Bruce,
> 
> Based on pg_test_fsync results, should we choose open_datasync or fdatasync as
> wal_sync_method? Can we rely on pg_test_fsync for choosing the best

I would just pick the fastest method, but if the method is _too_ fast,
it might mean that it isn't actually writing to durable storage.

> wal_sync_method or is there any other way?

pg_test_fsync is the only way I know of, which is why I wrote it.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee