Re: Design for In-Core Logical Replication

On 20/07/16 19:07, Simon Riggs wrote:
> On 20 July 2016 at 16:39, Joshua D. Drake <jd(at)commandprompt(dot)com
> <mailto:jd(at)commandprompt(dot)com>> wrote:
> <para>
> Logical Replication uses a Publish and Subscribe model
> with one or
> more Subscribers subscribing to one or more Publications on a
> Provider node. Subscribers pull data from the Publications
> they
> subscribe to and may subsequently re-publish data to allow
> cascading replication or more complex configurations.
>
>
> Is that somehow different than Origin/Subscriber or Master/Slave? If
> not, why are we using yet more terms?
>
>
> Thanks for asking, an important question that we have a chance to get
> right before we go too far down the road of implementation.
>
> I'll explain my thinking, so we can discuss the terms I've recommended,
> which can be summarized as:
> A Provider node has one or more Databases, each of which can publish its
> data in zero, one or more PUBLICATIONs. A Subscribing node can receive
> data in the form of zero, one or more SUBSCRIBERs, where each SUBSCRIBER
> may bring together data from one or more PUBLICATIONs
>
> Here's why...
>

Just to add to what Simon wrote. There is one more reason for not using
term origin for this - origin of data does not necessarily have to be on
the provider database once there is a cascading so it does not really
map all that well.

--
Petr Jelinek http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services