CREATE SUBSCRIPTION mysub WITH CONNECTION <quote>dbname=foo host=bar user=repuser</quote> PUBLICATION mypub;
</programlisting>
</para>
<para>
The above will start the replication process which synchronizes the
initial table contents of <literal>users</literal> and
<literal>departments</literal> tables and then starts replicating
incremental changes to those tables.
</para>
</sect1>
</chapter>
I think it's important for communication channels to be defined separately from the subscriptions.
If I have nodes 1/2 + 3/4 which operate in pairs, I don't really want to have to have a script reconfigure replication on 3/4 every-time we do maintenance on 1 or 2.
3/4 need to know they subscribe to mypub and that they have connections to machine 1 and machine 2. The replication system should be able to figure out which (of 1/2) has the most recently available data.
Notice I explicitly did not tell it how to get the publication but if we did have a preference the DNS weighting model might be appropriate.
I'm not certain the subscription needs to be named. IMO, a publication should have the same properties on all nodes (so any node may become the primary source). If a subscriber needs different behaviour for a publication, it should be created as a different publication.
Documenting that ThisPub is different from ThatPub is easier than documenting that ThisPub on node 1/2/4 is different from ThisPub on node 7/8, except Node 7 is temporarily on Node 4 too (database X instead of database Y) due to that power problem.
Clearly this is advanced. An initial implementation may only allow mypub from a single connection.
I also suspect multiple publications will be normal even if only 2 nodes. Old slow moving data almost always got different treatment than fast-moving data; even if only defining which set needs to hit the other node first and which set can trickle through later.
