Re: Ambiguous description on new columns

Hi,

Le mar. 21 mai 2024 à 12:40, PG Doc comments form <noreply(at)postgresql(dot)org>
a écrit :

> The following documentation comment has been logged on the website:
>
> Page:
> https://www.postgresql.org/docs/16/logical-replication-col-lists.html
> Description:
>
> The documentation on this page mentions:
>
> "If no column list is specified, any columns added later are automatically
> replicated."
>
> It feels ambiguous what this could mean. Does it mean:
>
> 1/ That if you alter the table on the publisher and add a new column, it
> will be replicated
>
> 2/ If you add a column list later and add a column to it, it will be
> replicated
>
> In both cases, does the subscriber automatically create this column if it
> wasn't there before? I recall reading that the initial data synchronization
> requires the schema of the publisher database to be created on the
> subscriber first. But then later updates sync newly created columns? I
> don't
> recall any pages on logical replication mentioning this, up to this point.
>
>
It feels ambiguous. DDL commands are not replicated, so the new columns
don't appear automagically on the subscriber. You have to add them to the
subscriber. But values of new columns are replicated, whether or not you
have added the new columns on the subscriber.

Regards.

--
Guillaume.