Re: Pgoutput not capturing the generated columns

On Fri, Sep 20, 2024 at 4:16 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> On Fri, Sep 20, 2024 at 3:26 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > On Thu, Sep 19, 2024 at 2:32 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > >
> > >
> > > Users can use a publication like "create publication pub1 for table
> > > t1(c1, c2), t2;" where they want t1's generated column to be published
> > > but not for t2. They can specify the generated column name in the
> > > column list of t1 in that case even though the rest of the tables
> > > won't publish generated columns.
> >
> > Agreed.
> >
> > I think that users can use the publish_generated_column option when
> > they want to publish all generated columns, instead of specifying all
> > the columns in the column list. It's another advantage of this option
> > that it will also include the future generated columns.
> >
>
> OK. Let me give some examples below to help understand this idea.
>
> Please correct me if these are incorrect.
>
> Examples, when publish_generated_columns=true:
>
> CREATE PUBLICATION pub1 FOR t1(a,b,gen2), t2 WITH
> (publish_generated_columns=true)
> t1 -> publishes a, b, gen2 (e.g. what column list says)
> t2 -> publishes c, d + ALSO gen1, gen2
>
> CREATE PUBLICATION pub1 FOR t1, t2(gen1) WITH (publish_generated_columns=true)
> t1 -> publishes a, b + ALSO gen1, gen2
> t2 -> publishes gen1 (e.g. what column list says)
>

These two could be controversial because one could expect that if
"publish_generated_columns=true" then publish generated columns
irrespective of whether they are mentioned in column_list. I am of the
opinion that column_list should take priority the results should be as
mentioned by you but let us see if anyone thinks otherwise.

>
> ======
>
> The idea LGTM, although now the parameter name
> ('publish_generated_columns') seems a bit misleading since sometimes
> generated columns get published "irrespective of the option".
>
> So, I think the original parameter name 'include_generated_columns'
> might be better here because IMO "include" seems more like "add them
> if they are not already specified", which is exactly what this idea is
> doing.
>

I still prefer 'publish_generated_columns' because it matches with
other publication option names. One can also deduce from
'include_generated_columns' that add all the generated columns even
when some of them are specified in column_list.

--
With Regards,
Amit Kapila.