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? -- Regards, Dilip Kumar EnterpriseDB: http://www.enterprisedb.com
