From: Tom Lane <tgl@sss.pgh.pa.us>
To: Marc Millas <marc.millas@mokadb.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: 9.6 write time
Date: Tue, 28 Dec 2021 12:46:44 -0500
Message-ID: <1905390.1640713604@sss.pgh.pa.us> (raw)
In-Reply-To: <CADX_1ab-t3Lderkh_bB4_F60RVgN9UkR1UvYKSmE8WEdEAbDwQ@mail.gmail.com>
References: <CADX_1ab-t3Lderkh_bB4_F60RVgN9UkR1UvYKSmE8WEdEAbDwQ@mail.gmail.com>
Marc Millas <marc.millas@mokadb.com> writes:
> I am looking at a postgres 9.6 on rh7
> I see that checkpoint_write_time is huge which looks quite strange as the
> average amount of data written is not that big.
checkpoint_write_time is not the amount of time spent doing I/O;
it's the elapsed wall-clock time in the write phase. If the I/O
is being throttled because of an un-aggressive checkpoint completion
target, it could be a lot more than the actual I/O time. What have
you got your checkpoint parameters set to?
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, marc.millas@mokadb.com
Subject: Re: 9.6 write time
In-Reply-To: <1905390.1640713604@sss.pgh.pa.us>
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