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help / color / mirror / Atom feedFrom: Laurenz Albe <laurenz.albe@cybertec.at>
To: Subramanian,Ramachandran <ramachandran.subramanian@alte-leipziger.de>
To: pgsql-novice@lists.postgresql.org <pgsql-novice@lists.postgresql.org>
Subject: Re: AW: AW: Replication Testing- How to introduce a Lag
Date: Sat, 21 Mar 2026 09:43:10 +0100
Message-ID: <fc42f77c80fdb3c0267148b807edfacc49b0b0ca.camel@cybertec.at> (raw)
In-Reply-To: <fa47fe18078043adbdfe007b7270ffd0@alte-leipziger.de>
References: <aadb9058660d4e10b5cee44b82458802@alte-leipziger.de>
<f3927bc3a9baf4400325b91652869907f0581c97.camel@cybertec.at>
<e1e41761323040228570cf6a7e02518e@alte-leipziger.de>
<8b38fa5141905f9ad6983b8d5ae944e812e3d28a.camel@cybertec.at>
<fa47fe18078043adbdfe007b7270ffd0@alte-leipziger.de>
On Sat, 2026-03-21 at 07:49 +0000, Subramanian,Ramachandran wrote:
> > Look at "pg_stat_replication" on the primary server.
>
> If I just look at the write_lag columns, it would give me a good idea of the situation -- Is my understanding correct ?
Yes, but if no WAL gets generated and replicated for a while, the columns will
become NULL, because then delay measured in time makes no sense.
Therefore, I prefer to use "replay_lsn" and friends and measure the lag in bytes.
Yours,
Laurenz Albe
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To: pgsql-novice@postgresql.org
Cc: laurenz.albe@cybertec.at, ramachandran.subramanian@alte-leipziger.de, pgsql-novice@lists.postgresql.org
Subject: Re: AW: AW: Replication Testing- How to introduce a Lag
In-Reply-To: <fc42f77c80fdb3c0267148b807edfacc49b0b0ca.camel@cybertec.at>
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