Hello, We recently noticed some behavior that seems reasonable but also surprised our engineers based on the docs.
If we have this setup: create table items(i int); insert into items(i) values (1); create publication test_pub for all tables; Then when we: delete from items where i = 1; we get: ERROR: cannot delete from table "items" because it does not have a replica identity and publishes deletes HINT: To enable deleting from the table, set REPLICA IDENTITY using ALTER TABLE. Fair enough. But if we do this: alter table items replica identity nothing; because the docs [1] say that NOTHING means "Records no information about the old row." We still get the same error when we try the DELETE again. The publication docs [2] say "A published table must have a replica identity configured in order to be able to replicate UPDATE and DELETE operations, so that appropriate rows to update or delete can be identified on the subscriber side." We interpreted the intersection of these two docs to imply that if you explicitly configured NOTHING that the publication would simply not log anything about the original row. Part of the confusion I think was fed by reading "must have a replica identity set" as "have selected one of the options via ALTER TABLE REPLICA IDENTITY" -- i.e., as meaning that a setting has been configured rather than being about a subset of those possible configuration values/a specific key existing on the table. I'm wondering if this might be a surprise to anyone else, and if so, is there a minor docs tweak that might avoid the confusion? Thanks, James Coleman 1: https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-REPLICA-IDENTITY 2: https://www.postgresql.org/docs/current/logical-replication-publication.html
