Postgres Pro
Downloads
Home   >   mailing lists

Thread: logical replication

logical replication

From
Marc Millas
Date:
Hi,

my POC in postgres 12.(important ?)

if I setup 2 postgres clusters, and create a publication in one and a subscription in the other,
and do on the pub an update which does not change the data (updating an existing record with same data) then this (useless) update go through replication.(ie consumes network ressource)

what are ways to avoid this ?
(I thought of a trigger to not execute the useless update, but I dont see how to do this)
any ideas ?

thanks
PS: remarks about the meaning of this are off topic, thanks

Marc MILLAS
Senior Architect
+33607850334

Re: logical replication

From
Andrew Dunstan
Date:
On 5/21/21 8:41 AM, Marc Millas wrote:
> Hi,
>
> my POC in postgres 12.(important ?)
>
> if I setup 2 postgres clusters, and create a publication in one and a
> subscription in the other,
> and do on the pub an update which does not change the data (updating
> an existing record with same data) then this (useless) update go
> through replication.(ie consumes network ressource)
>
> what are ways to avoid this ?
> (I thought of a trigger to not execute the useless update, but I
> dont see how to do this)
> any ideas ?
>
> thanks
> PS: remarks about the meaning of this are off topic, thanks
>
>

Postgres provides exactly such a trigger. See
https://www.postgresql.org/docs/12/functions-trigger.html


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Re: logical replication

From
Marc Millas
Date:
perfect :-)

thanks

Marc MILLAS
Senior Architect
+33607850334



On Fri, May 21, 2021 at 3:21 PM Andrew Dunstan <andrew@dunslane.net> wrote:

On 5/21/21 8:41 AM, Marc Millas wrote:
> Hi,
>
> my POC in postgres 12.(important ?)
>
> if I setup 2 postgres clusters, and create a publication in one and a
> subscription in the other,
> and do on the pub an update which does not change the data (updating
> an existing record with same data) then this (useless) update go
> through replication.(ie consumes network ressource)
>
> what are ways to avoid this ?
> (I thought of a trigger to not execute the useless update, but I
> dont see how to do this)
> any ideas ?
>
> thanks
> PS: remarks about the meaning of this are off topic, thanks
>
>

Postgres provides exactly such a trigger. See
https://www.postgresql.org/docs/12/functions-trigger.html


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com