Re: row filtering for logical replication

On Wed, Apr 13, 2022 at 10:01 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> BTW I just noticed that AlterPublicationOptions acquires only
> ShareAccessLock on the publication object.  I think this is too lax ...
> what if two of them run concurrently? (say to specify different
> published actions)  Do they overwrite the other's update?
>

No, they won't overwrite. Firstly the AccessShareLock on the
publication object is not related to concurrent change of the
publication object. They will be protected by normal update-row rules
(like till the first transaction finishes, the other will wait). See
an example below:

Session-1
postgres=# Begin;
BEGIN
postgres=*# Alter publication pub1 set (publish = 'insert');
ALTER PUBLICATION

Session-2:
postgres=# Begin;
BEGIN
postgres=*# Alter publication pub1 set (publish = 'update');

The Alter in Session-2 will wait till we end the transaction in Session-1.


-- 
With Regards,
Amit Kapila.