On Sun, Jan 12, 2025 at 11:00 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Sat, Jan 11, 2025 at 7:28 PM Robert Treat <r...@xzilla.net> wrote: > > > > Definitely couldn't hurt; Updated patch cleans that up a bit and > > tweaks the link to alter table replica status. > > > > IIUC, we have changed following to clarify the REPLICA IDENTITY usage: > If a table without a replica identity is > - added to a publication that replicates <command>UPDATE</command> > - or <command>DELETE</command> operations then > - subsequent <command>UPDATE</command> or <command>DELETE</command> > - operations will cause an error on the publisher. > <command>INSERT</command> > - operations can proceed regardless of any replica identity. > > + If a table with replica identity set to <literal>NOTHING</literal> > + (or set <command>DEFAULT</command> but with no primary key, or set > + <command>USING INDEX</command> but the index has been dropped) is > + added to a publication that replicates <command>UPDATE</command> > + or <command>DELETE</command> operations, > + subsequent <command>UPDATE</command> or <command>DELETE</command> > + operations will cause an error on the publisher. > > In the above change, we missed the existing "a table without a replica > identity" part. A slightly different way to write the above change > could be: "Tables lacking a replica identity or with an insufficiently > defined replica identity (e.g., set to NOTHING, set to DEFAULT but > with no primary key, or set USING INDEX but the index has been > dropped) cannot be updated or deleted when added to a publication that > replicates these operations. Attempting to do so will result in an > error on the publisher." >
We didn't miss it, we removed it. It is a misnomer to say a table doesn't have a replica identity, because all tables do and always must have one, hence pg_class.relreplident is NOT NULL. In most cases it is set DEFAULT and people don't think about it, but it isn't due to a lack of or insufficient replica identity, and I think that language is part of what confuses people. Aside from that, your above language is a little more compact with the trade-off of being less explicit in talking about publication properties; I didn't change that part because it didn't seem like an issue, but we could update that second part if you feel strongly about it. LMK. Robert Treat https://xzilla.net
