On Wed, Apr 26, 2023 at 2:56 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Wed, Apr 26, 2023 at 10:01 AM Masahiko Sawada <sawada.m...@gmail.com> > wrote: > > > > On Tue, Apr 25, 2023 at 12:58 PM Zhijie Hou (Fujitsu) > > <houzj.f...@fujitsu.com> wrote: > > > > > > Aport from above comments, I splitted the code related to verbose > > > mode to a separate patch. And here is the new version patch set. > > > > > > > As for DDL replication, we create event triggers to write deparsed DDL > > commands to WAL when creating a publication with the ddl option. The > > event triggers are recreated/dropped at ALTER/DROP PUBLICATION. I'm > > concerned it's possible that DDLs executed while such a publication > > not existing are not replicated. For example, imagine the following > > steps, > > > > 1. CREATE PUBLICATION test_pub ... WITH (ddl = 'table); > > 2. CREATE SUBSCRIPTION test_sub ... PUBLICATION test_pub; > > 3. ALTER SUBSCRIPTION test_sub DISABLE; > > 4. DROP PUBLICATION test_pub; > > 5. CREATE PUBLICATION test_pub ... WITH (ddl = 'table); > > 6. ALTER SUBSCRIPTION test_sub ENABLE; > > > > DDLs executed between 4 and 5 won't be replicated. > > > > But we won't even send any DMLs between 4 and 5. In fact, WALSender > will give an error for those DMLs that publication doesn't exist as it > uses a historic snapshot.
You're right, I missed this point. > So, why do we expect DDLs between Drop and > Create of publication should be replicated? For example, suppose that a publication is created for a table and then a new column is added to the table between 4 and 5, subsequent INSERTs could fail due to the missing column. But it's not a problem as you pointed out since the user dropped the publication. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
