write on standby

Started by Julie Nishimuraabout 7 years ago6 messagesgeneral
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#1Julie Nishimura
juliezain@hotmail.com

Hello there,
Is it possible for a test app to connect to the standby dB of an active-Standby dB pair? While both continue to be connected and replicating? What if it’s needed to write tmp tables that are later dropped? Can it be done in hot standby scenario on standby? Version is 9.6.2

Thanks

#2Adrian Klaver
adrian.klaver@aklaver.com
In reply to: Julie Nishimura (#1)
Re: write on standby

On 3/5/19 3:34 PM, Julie Nishimura wrote:

Hello there,
Is it possible for a test app to connect to the standby dB of an
active-Standby dB pair? �While both continue to be connected and
replicating? What if it�s needed to write tmp tables that are later
dropped? Can it be done in hot standby scenario on standby? Version is 9.6.2

No:

https://www.postgresql.org/docs/9.6/hot-standby.html

26.5.1. User's Overview

In particular:

"Data Definition Language (DDL) - CREATE, DROP, ALTER, COMMENT. This
restriction applies even to temporary tables, because carrying out these
operations would require updating the system catalog tables."

Thanks

--
Adrian Klaver
adrian.klaver@aklaver.com

#3Andreas Kretschmer
andreas@a-kretschmer.de
In reply to: Julie Nishimura (#1)
Re: write on standby

Am 06.03.19 um 00:34 schrieb Julie Nishimura:

Hello there,
Is it possible for a test app to connect to the standby dB of an
active-Standby dB pair?

that's possible, but ...

While both continue to be connected and replicating? What if it�s
needed to write tmp tables that are later dropped?

... that's not. Not with streaming replication, but ...

Can it be done in hot standby scenario on standby? Version is 9.6.2

... it would be possible with logical replication (trigger based
solutions like slony or lindiste or logical replication using pglogical
from us, 2ndQ).

https://www.2ndquadrant.com/en/resources/pglogical/

You can also use BDR2 with PG9.6, but this is only available for our
customers.

Regards, Andreas

--
2ndQuadrant - The PostgreSQL Support Company.
www.2ndQuadrant.com

#4Julie Nishimura
juliezain@hotmail.com
In reply to: Andreas Kretschmer (#3)
Re: write on standby

Thank you. Are you going to have any presentations on Postgresql conference in NYC soon?

________________________________
From: Andreas Kretschmer <andreas@a-kretschmer.de>
Sent: Tuesday, March 5, 2019 9:16 PM
To: pgsql-general@lists.postgresql.org
Subject: Re: write on standby

Am 06.03.19 um 00:34 schrieb Julie Nishimura:

Hello there,
Is it possible for a test app to connect to the standby dB of an
active-Standby dB pair?

that's possible, but ...

While both continue to be connected and replicating? What if it’s
needed to write tmp tables that are later dropped?

... that's not. Not with streaming replication, but ...

Can it be done in hot standby scenario on standby? Version is 9.6.2

... it would be possible with logical replication (trigger based
solutions like slony or lindiste or logical replication using pglogical
from us, 2ndQ).

https://www.2ndquadrant.com/en/resources/pglogical/

You can also use BDR2 with PG9.6, but this is only available for our
customers.

Regards, Andreas

--
2ndQuadrant - The PostgreSQL Support Company.
www.2ndQuadrant.com<http://www.2ndQuadrant.com&gt;

#5Andreas Kretschmer
andreas@a-kretschmer.de
In reply to: Julie Nishimura (#4)
Re: write on standby

On 6 March 2019 06:26:45 CET, Julie Nishimura <juliezain@hotmail.com> wrote:

Thank you. Are you going to have any presentations on Postgresql
conference in NYC soon?

________________________________
From: Andreas Kretschmer <andreas@a-kretschmer.de>
Sent: Tuesday, March 5, 2019 9:16 PM
To: pgsql-general@lists.postgresql.org
Subject: Re: write on standby

Am 06.03.19 um 00:34 schrieb Julie Nishimura:

Hello there,
Is it possible for a test app to connect to the standby dB of an
active-Standby dB pair?

that's possible, but ...

While both continue to be connected and replicating? What if it’s
needed to write tmp tables that are later dropped?

... that's not. Not with streaming replication, but ...

Can it be done in hot standby scenario on standby? Version is 9.6.2

... it would be possible with logical replication (trigger based
solutions like slony or lindiste or logical replication using pglogical
from us, 2ndQ).

https://www.2ndquadrant.com/en/resources/pglogical/

You can also use BDR2 with PG9.6, but this is only available for our
customers.

Regards, Andreas

--
2ndQuadrant - The PostgreSQL Support Company.
www.2ndQuadrant.com<http://www.2ndQuadrant.com&gt;

Hi,

I think so, if you want i can organize a contact with someone from our company.

Andreas (from germany)
--
2ndQuadrant - The PostgreSQL Support Company

#6Adrian Klaver
adrian.klaver@aklaver.com
In reply to: Andreas Kretschmer (#3)
Re: write on standby

On 3/5/19 9:16 PM, Andreas Kretschmer wrote:

Am 06.03.19 um 00:34 schrieb Julie Nishimura:

Hello there,
Is it possible for a test app to connect to the standby dB of an
active-Standby dB pair?

that's possible, but ...

While both continue to be connected and replicating? What if it�s
needed to write tmp tables that are later dropped?

... that's not. Not with streaming replication, but ...

Can it be done in hot standby scenario on standby? Version is 9.6.2

... it would be possible with logical replication (trigger based
solutions like slony or lindiste or logical replication using pglogical
from us, 2ndQ).

https://www.2ndquadrant.com/en/resources/pglogical/

You can also use BDR2 with PG9.6, but this is only available for our
customers.

Out of curiosity how did:

/messages/by-id/20150831193033.GL2912@alvherre.pgsql

/messages/by-id/CAH+GA0qO0q9NJhKxaoo8CV-QR9Cuw6LtDGDb33pq16rU88F_dA@mail.gmail.com

get to?:

https://www.2ndquadrant.com/en/resources/postgres-bdr-2ndquadrant/

Regards, Andreas

--
Adrian Klaver
adrian.klaver@aklaver.com