Subject: Re: Skipping logical replication transactions on subscriber side
To: Amit Kapila <amit.kapila16@gmail.com>,
 Masahiko Sawada <sawada.mshk@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
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From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Message-ID: <bd954841-596d-c212-9a13-6f9747cc8903@enterprisedb.com>
Date: Mon, 31 May 2021 21:25:55 +0200
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On 27.05.21 12:04, Amit Kapila wrote:
>>> Also, I am thinking that instead of a stat view, do we need
>>> to consider having a system table (pg_replication_conflicts or
>>> something like that) for this because what if stats information is
>>> lost (say either due to crash or due to udp packet loss), can we rely
>>> on stats view for this?
>> Yeah, it seems better to use a catalog.
>>
> Okay.

Could you store it shared memory?  You don't need it to be crash safe, 
since the subscription will just run into the same error again after 
restart.  You just don't want it to be lost, like with the statistics 
collector.