Logical decoding on standby

Started by Andreas Joseph Kroghabout 8 years ago7 messagesgeneral
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#1Andreas Joseph Krogh
andreas@visena.com

Anybody knows if $subject will make it into v11?
 
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Andreas Joseph Krogh

#2Andreas Kretschmer
andreas@a-kretschmer.de
In reply to: Andreas Joseph Krogh (#1)
Re: Logical decoding on standby

On 12 March 2018 21:18:22 CET, Andreas Joseph Krogh <andreas@visena.com> wrote:

Anybody knows if $subject will make it into v11?
 
--
Andreas Joseph Krogh

Why do you think you needs this?

Regards, Andreas

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2ndQuadrant - The PostgreSQL Support Company

#3Andreas Kretschmer
andreas@a-kretschmer.de
In reply to: Andreas Kretschmer (#2)
Re: Logical decoding on standby

On 13 March 2018 00:58:27 CET, Andreas Kretschmer <andreas@a-kretschmer.de> wrote:

On 12 March 2018 21:18:22 CET, Andreas Joseph Krogh
<andreas@visena.com> wrote:

Anybody knows if $subject will make it into v11?
 
--
Andreas Joseph Krogh

Why do you think you needs this?

Regards, Andreas

Let me explain my question. One of the key aspects of logical replication is, that you can define what to replicate. That wouldn't work in this way, that's why i'm asking.

Regards, Andreas

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2ndQuadrant - The PostgreSQL Support Company

#4David G. Johnston
david.g.johnston@gmail.com
In reply to: Andreas Kretschmer (#3)
Re: Logical decoding on standby

On Mon, Mar 12, 2018 at 5:08 PM, Andreas Kretschmer <andreas@a-kretschmer.de

wrote:

Let me explain my question. One of the key aspects of logical replication
is, that you can define what to replicate. That wouldn't work in this way,
that's why i'm asking.

One of the key aspects of "standby" is that it is ready to be a drop-in
replacement for the "active" server, and today our logical replication
facility is not capable of ensuring that property and won't be for v11 that
I can tell. I'm not certain that said capability is even a goal at present.

IOW, why do you need a "standby" that isn't a drop-in replacement for a
primary - i.e., can have a filter on what replicated data it accepts?

David J.

#5Andreas Joseph Krogh
andreas@visena.com
In reply to: Andreas Kretschmer (#3)
Sv: Re: Logical decoding on standby

På tirsdag 13. mars 2018 kl. 01:08:03, skrev Andreas Kretschmer <
andreas@a-kretschmer.de <mailto:andreas@a-kretschmer.de>>:
On 13 March 2018 00:58:27 CET, Andreas Kretschmer <andreas@a-kretschmer.de>
wrote:

On 12 March 2018 21:18:22 CET, Andreas Joseph Krogh
<andreas@visena.com> wrote:

Anybody knows if $subject will make it into v11?
 
--
Andreas Joseph Krogh

Why do you think you needs this?

Regards, Andreas

Let me explain my question. One of the key aspects of logical replication is,
that you can define what to replicate. That wouldn't work in this way, that's
why i'm asking.

Regards, Andreas
 
I have streaming-replication of a cluster containing many databases to a
standby-server. I need a reporting-server which only needs a subset of some
(large) tables of one database and am planning to use the built-in logical
replication for that. It is my understanding that logical replication will
cause more wal-traffic so I'm trying to offload wal-traffic from the primary. I
thought using logical replication from the standby would help with that but
realized it's not supported in v10. Im I wrong in planning this way?
 
-- Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andreas@visena.com <mailto:andreas@visena.com>
www.visena.com <https://www.visena.com&gt;
<https://www.visena.com&gt;

 

#6Andres Freund
andres@anarazel.de
In reply to: Andreas Kretschmer (#3)
Re: Logical decoding on standby

Hi,

On 2018-03-13 01:08:03 +0100, Andreas Kretschmer wrote:

On 13 March 2018 00:58:27 CET, Andreas Kretschmer <andreas@a-kretschmer.de> wrote:

On 12 March 2018 21:18:22 CET, Andreas Joseph Krogh
<andreas@visena.com> wrote:

Anybody knows if $subject will make it into v11?

I can't see it happening for v11, there's not even a CF entry in the
last CF.

Why do you think you needs this?

Regards, Andreas

Let me explain my question. One of the key aspects of logical replication is, that you can define what to replicate. That wouldn't work in this way, that's why i'm asking.

The subject said logical decoding, not replication. There's a lot of
change data capture type workloads where decoding from the standby is
quite useful. And the design definitely would work for that, we've
explicitly took that into consideration.

Greetings,

Andres Freund

#7Andreas Kretschmer
andreas@a-kretschmer.de
In reply to: Andres Freund (#6)
Re: Logical decoding on standby

Am 13.03.2018 um 02:40 schrieb Andres Freund:

The subject said logical decoding, not replication. There's a lot of
change data capture type workloads where decoding from the standby is
quite useful. And the design definitely would work for that, we've
explicitly took that into consideration.

Greetings,

Andres Freund

Ah, thx, didn't know that.

Regards, Andreas

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