Message-ID: <962b9015-201c-9df6-d79e-8e6afad21a93@enterprisedb.com>
Date: Mon, 22 Nov 2021 16:44:57 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.3.2
Subject: Re: logical decoding and replication of sequences
Content-Language: en-US
To: Tomas Vondra <tomas.vondra@enterprisedb.com>,
 Hannu Krosing <hannuk@google.com>
Cc: vignesh C <vignesh21@gmail.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 Petr Jelinek <petr.jelinek@enterprisedb.com>
References: <d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com>
 <377c6fda-c3eb-7a69-e981-c77ae459c5db@enterprisedb.com>
 <bb890134-a566-efbc-f418-cd0f92eb4b70@enterprisedb.com>
 <5105c3ad-d726-fc22-1d09-514b6852a15e@enterprisedb.com>
 <CALDaNm3gZZjBKWs7gufQep9ikJMtoY9Xv4CsYTpYRaT720RpbQ@mail.gmail.com>
 <3005299b-267d-8e4a-68a3-abdad3e96aba@enterprisedb.com>
 <3d6df331-5532-6848-eb45-344b265e0238@enterprisedb.com>
 <482c10c1-b110-819f-b0e7-17549fa2f0dc@enterprisedb.com>
 <12a9ecd6-4edb-a367-33da-4e2d03b0aace@enterprisedb.com>
 <CAMT0RQQeDR51xs8zTa25YpfKB1B34nS-Q4hhsRPznVsjMB_P1w@mail.gmail.com>
 <bdc688ef-9339-8234-d786-409f1e603711@enterprisedb.com>
 <e6ef8862-31e4-1582-9274-f8f57b7f1cab@enterprisedb.com>
 <2cd38bab-c874-8e0b-98e7-d9abaaf9806a@enterprisedb.com>
From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
In-Reply-To: <2cd38bab-c874-8e0b-98e7-d9abaaf9806a@enterprisedb.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Archived-At: 
 <https://www.postgresql.org/message-id/962b9015-201c-9df6-d79e-8e6afad21a93%40enterprisedb.com>
Precedence: bulk

On 22.11.21 01:47, Tomas Vondra wrote:
> So I think just decoding the sequence tuples is a better solution - for 
> large transactions (consuming many values from the sequence) it may be 
> more expensive (i.e. send more records to replica). But I doubt that 
> matters too much - it's likely negligible compared to other data for 
> large transactions.

I agree that the original approach is better.  It was worth trying out 
this alternative, but it seems quite complicated.  I note that a lot of 
additional code had to be added around several areas of the code, 
whereas the original patch really just touched the logical decoding 
code, as it should.  This doesn't prevent anyone from attempting to 
optimize things somehow in the future, but for now let's move forward 
with the simple approach.