On 09/02/2015 03:56 PM, Bruce Momjian wrote:
> On Wed, Sep 2, 2015 at 02:41:46PM -0400, Robert Haas wrote:
>> 4. Therefore, I think that we should instead use logical replication,
>> which might be either synchronous or asynchronous. When you modify
>> one copy of the data, that change will then be replicated to all other
>> nodes. If you are OK with eventual consistency, this replication can
>> be asynchronous, and nodes that are off-line will catch up when they
>> are on-line. If you are not OK with that, then you must replicate
>> synchronously to every node before transaction commit; or at least you
>> must replicate synchronously to every node that is currently on-line.
>> This presents some challenges: logical decoding currently can't
>> replicate transactions that are still in process - replication starts
>> when the transaction commits. Also, we don't have any way for
>> synchronous replication to wait for multiple nodes. But in theory
>> those seem like limitations that can be lifted. Also, the GTM needs
>> to be aware that this stuff is happening, or it will DTWT. That too
>> seems like a problem that can be solved.
>
> Can you explain why logical replication is better than binary
> replication for this use-case?
>
Selectivity?
JD
--
Command Prompt, Inc. - http://www.commandprompt.com/ 503-667-4564
PostgreSQL Centered full stack support, consulting and development.
Announcing "I'm offended" is basically telling the world you can't
control your own emotions, so everyone else should do it for you.
