Message-ID: <fc42f77c80fdb3c0267148b807edfacc49b0b0ca.camel@cybertec.at>
Subject: Re: AW: AW: Replication Testing- How to introduce a Lag
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: "Subramanian,Ramachandran" <ramachandran.subramanian@alte-leipziger.de>,
  "pgsql-novice@lists.postgresql.org"	 <pgsql-novice@lists.postgresql.org>
Date: Sat, 21 Mar 2026 09:43:10 +0100
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On Sat, 2026-03-21 at 07:49 +0000, Subramanian,Ramachandran wrote:
> > Look at "pg_stat_replication" on the primary server.
>=20
> If I just look at the write_lag columns, it would give me a good idea of =
the situation --=C2=A0 Is my understanding correct ?

Yes, but if no WAL gets generated and replicated for a while, the columns w=
ill
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