Обсуждение: Logical replication alternative

Hi Yambu,

On Wed, Nov 04, 2020 at 12:55:02PM +0200, Yambu wrote:
> Hi
>
> May i know what is the alternative to logical replication if i want to
> replicate a few tables on postgres v10?

You may want to look into SkyTools[0], which provide the infrastructure to
enable trigger-based replication approaches via PgQ/Londiste.


[0]: https://wiki.postgresql.org/wiki/SkyTools

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Hi,

Why do you need an alternative to logical replication? Please tell us
why logical replication isn't for you.

Regards,

Holger


Am 04.11.20 um 11:55 schrieb Yambu:
> Hi
>
> May i know what is the alternative to logical replication if i want to
> replicate a few tables on postgres v10?
>
> regards

-- 
Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012

Okay,

updating some tables once a day isn't actually replication.

For this to happen, I would suggest you connect the two machines by using the Foreign Data Wrapper and then:

• set up a foreign table
  
• create a materialized view on the "slave" as "select * from foreign_table"
• set up a job for refreshing the materialized view

Regards,

Holger

Hi Holger

1. We want to update the few tables once a day

2. We want to avoid restart the mission critical database, changing wal_level requires a restart

regards 

On Wed, Nov 4, 2020 at 1:28 PM Holger Jakobs <holger@jakobs.com> wrote:

Hi,

Why do you need an alternative to logical replication? Please tell us
why logical replication isn't for you.

Regards,

Holger


Am 04.11.20 um 11:55 schrieb Yambu:
> Hi
>
> May i know what is the alternative to logical replication if i want to
> replicate a few tables on postgres v10?
>
> regards

--
Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012

-- 
Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012

Yambu schrieb am 04.11.2020 um 11:55:
> May i know what is the alternative to logical replication if i want
> to replicate a few tables on postgres v10?

What about using foreign tables?
Then no replication would be required.

If that is to slow, you could create a materialized view on the
"secondary" server that is based on the foreign tables.

You can refresh the MVIEW multiple times a day.

The downside is that this isn't incremental, you would always copy
all the data.

Thomas

On Wed, 2020-11-04 at 13:34 +0200, Yambu wrote:
> > Why do you need an alternative to logical replication? Please tell us
> > why logical replication isn't for you.
> 
> 1. We want to update the few tables once a day
> 2. We want to avoid restart the mission critical database, changing wal_level requires a restart

I think that you should plan the restart - it is only a short downtime.

All the other solutions (Skytools, Slony, ...) are way more invasive:
they will create triggers on your precious database, which can slow
down data modifications considerably.

Yours,
Laurenz Albe
-- 
Cybertec | https://www.cybertec-postgresql.com