From: Fabien COELHO <coelho@cri.ensmp.fr>
To: Hannu Krosing <hannuk@google.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: nagata@sraoss.co.jp, gregsmithpgsql@gmail.com, pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: david.christensen@crunchydata.com
Subject: Re: pgbench logging broken by time logic changes
Date: Thu, 8 Jul 2021 19:25:38 +0200 (CEST)
Message-ID: <alpine.DEB.2.22.394.2107081920160.233209@pseudo> (raw)
In-Reply-To: <CAMT0RQReCH-VO6fko4i9=iZLT9qNL5YUnX0Zbt_d-_V9zUCyCg@mail.gmail.com>
References: <20210617025138.04a35c3ae9a6cd40c077cea0@sraoss.co.jp>
<alpine.DEB.2.22.394.2106162102030.2407635@pseudo>
<20210617122342.74aa8e65b186a7f2e0034533@sraoss.co.jp>
<20210617.141756.654908256727895408.horikyota.ntt@gmail.com>
<CAMT0RQReCH-VO6fko4i9=iZLT9qNL5YUnX0Zbt_d-_V9zUCyCg@mail.gmail.com>
Hello Hannu,
>> I'm not sure we have transaction lasts for very short time that
>> nanoseconds matters.
>
> Nanoseconds may not matter yet, but they could be handy when for
> example we want to determine the order of parallel query executions.
>
> We are less than an order of magnitude away from being able to do 1M
> inserts/updates/deletes per second, so microseconds already are not
> always 100% reliable.
ISTM that 1M tps would be with really a lot of parallel clients, thus the
latency of each would be quite measurable, so that µs would still make
sense for measuring their performance? If an actual network is involved,
the network latency is already 100-200 µs even before executing any code.
--
Fabien.
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To: pgsql-hackers@postgresql.org
Cc: coelho@cri.ensmp.fr, hannuk@google.com, horikyota.ntt@gmail.com, david.christensen@crunchydata.com
Subject: Re: pgbench logging broken by time logic changes
In-Reply-To: <alpine.DEB.2.22.394.2107081920160.233209@pseudo>
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