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logical replication
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* logical replication
@ 2021-05-21 12:41 Marc Millas <marc.millas@mokadb.com>
  2021-05-21 13:21 ` Re: logical replication Andrew Dunstan <andrew@dunslane.net>
  0 siblings, 1 reply; 3+ messages in thread

From: Marc Millas @ 2021-05-21 12:41 UTC (permalink / raw)
  To: pgsql-performance

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
www.mokadb.com

^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: logical replication
  2021-05-21 12:41 logical replication Marc Millas <marc.millas@mokadb.com>
@ 2021-05-21 13:21 ` Andrew Dunstan <andrew@dunslane.net>
  2021-05-21 13:44   ` Re: logical replication Marc Millas <marc.millas@mokadb.com>
  0 siblings, 1 reply; 3+ messages in thread

From: Andrew Dunstan @ 2021-05-21 13:21 UTC (permalink / raw)
  To: Marc Millas <marc.millas@mokadb.com>; pgsql-performance


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






^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: logical replication
  2021-05-21 12:41 logical replication Marc Millas <marc.millas@mokadb.com>
  2021-05-21 13:21 ` Re: logical replication Andrew Dunstan <andrew@dunslane.net>
@ 2021-05-21 13:44   ` Marc Millas <marc.millas@mokadb.com>
  0 siblings, 0 replies; 3+ messages in thread

From: Marc Millas @ 2021-05-21 13:44 UTC (permalink / raw)
  To: Andrew Dunstan <andrew@dunslane.net>; +Cc: pgsql-performance

perfect :-)

thanks

Marc MILLAS
Senior Architect
+33607850334
www.mokadb.com



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
>
>

^ permalink  raw  reply  [nested|flat] 3+ messages in thread


end of thread, other threads:[~2021-05-21 13:44 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
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2021-05-21 12:41 logical replication Marc Millas <marc.millas@mokadb.com>
2021-05-21 13:21 ` Andrew Dunstan <andrew@dunslane.net>
2021-05-21 13:44   ` Marc Millas <marc.millas@mokadb.com>

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