On Mon, Mar 7, 2022 at 10:05 AM Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Mon, Mar 7, 2022 at 9:26 AM Dilip Kumar <dilipbal...@gmail.com> wrote: > > > > On Wed, Feb 23, 2022 at 11:59 AM vignesh C <vignes...@gmail.com> wrote: > > > Here there are two problems for the user: a) incremental > > > synchronization of table sending both local data and replicated data > > > by walsender b) Table synchronization of table using copy command > > > sending both local data and replicated data > > > > > > For the first problem "Incremental synchronization of table by > > > Walsender" can be solved by: > > > Currently the locally generated data does not have replication origin > > > associated and the data that has originated from another instance will > > > have a replication origin associated. We could use this information to > > > differentiate locally generated data and replicated data and send only > > > the locally generated data. This "only_local" could be provided as an > > > option while subscription is created: > > > ex: CREATE SUBSCRIPTION sub1 CONNECTION 'dbname =postgres port=5433' > > > PUBLICATION pub1 with (only_local = on); > > > > I haven't yet gone through the patch, but I have a question about the > > idea. Suppose I want to set up a logical replication like, > > node1->node2->node3->node1. So how would I create the subscriber at > > node1? only_local=on or off?. I mean on node1, I want the changes > > from node3 which are generated on node3 or which are replicated from > > node2 but I do not want changes that are replicated from node1 itself? > > So if I set only_local=on then node1 will not get the changes > > replicated from node2, is that right? and If I set only_local=off then > > it will create the infinite loop again? So how are we protecting > > against this case? > > > > In the above topology if you want local changes from both node3 and > node2 then I think the way to get that would be you have to create two > subscriptions on node1. The first one points to node2 (with > only_local=off) and the second one points to node3 (with only_local > =off). >
Sorry, I intend to say 'only_local=on' at both places in my previous email. -- With Regards, Amit Kapila.
