Re: Skipping schema changes in publication

On Tue, Jun 17, 2025 at 5:41 PM Shlok Kyal <shlok.kyal.oss@gmail.com> wrote:
...
> I have attached a patch support excluding columns for publication.
>
> I have added a syntax: "FOR TABLE table_name EXCEPT (c1, c2, ..)"
> It can be used with CREATE or ALTER PUBLICATION.
>
> v12-0003 patch contains the changes for the same.
>

Hi Shlok,

I was interested in your new EXCEPT (col-list) so I had a quick look
at your patch v12-0003 (only looked at the documentation).

Below are some comments:

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1. Chapter 29.5 "Column Lists".

I think new EXCEPT syntax needs a mention here as well.

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doc/src/sgml/catalogs.sgml

2.
+      <para>
+       This is an array of values that indicates which table columns are
+       excluded from the publication.  For example, a value of
+       <literal>1 3</literal> would mean that the columns except the first and
+       the third columns are published.
+       A null value indicates that no columns are excluded from being
published.
+      </para></entry>

The sentence "A null value indicates that no columns are excluded from
being published" seems kind of confusing, because if the user has a
"normal" column-list  although nothing was being *explicitly* excluded
(using EXCEPT), any columns not named are *implicitly* excluded from
being published.

~

3.
TBH, I was wondering why a new catalog attribute was necessary...

Can't you simply re-use the existing attribute "prattrs" attribute.
e.g. let's just define negative means exclude.

e.g. a value of 1 3 means only the 1st and 3rd columns are published
e.g. a value of -1 -3 means all columns except 1st and 3rd columns are published
e.g. a value of null mean all columns are published

(mixes of negative and positive will not be possible)

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doc/src/sgml/ref/alter_publication.sgml

4. ALTER PUBLICATION syntax

The syntax is currently written as:
TABLE [ ONLY ] table_name [ * ] { [ [ ( column_name [, ... ] ) ] | [
EXCEPT ( column_name [, ... ] ) ] ] } [ WHERE ( expression ) ] [, ...
]

Can't this be more simply written as:
TABLE [ ONLY ] table_name [ * ] [ [ EXCEPT ] ( column_name [, ... ] )
] [ WHERE ( expression ) ] [, ... ]

~~~

5.
+  <para>
+   Alter publication <structname>mypublication</structname> to add table
+   <structname>users</structname> except column
+   <structname>security_pin</structname>:
+<programlisting>
+ALTER PUBLICATION production_publication ADD TABLE users EXCEPT (security_pin);

Those tags don't seem correct. e.g. "users" and "security_pin" are not
<structname> (???).

Perhaps, every other example here is wrong too and you just copied
them? Anyway, something here looks wrong to me.

======
doc/src/sgml/ref/create_publication.sgml

6. CREATE PUBLICATION syntax

The syntax is currently written as:
TABLE [ ONLY ] table_name [ * ] { [ [ ( column_name [, ... ] ) ] | [
EXCEPT ( column_name [, ... ] ) ] ] } [ WHERE ( expression ) ] [, ...
]

Can't this be more simply written as:
TABLE [ ONLY ] table_name [ * ] [ [ EXCEPT ] ( column_name [, ... ] )
] [ WHERE ( expression ) ] [, ... ]

~~~

7.
+     <para>
+      When a column list is specified with EXCEPT, the named columns are not
+      replicated. The excluded column list cannot contain generated
columns. The
+      column list and excluded column list cannot be specified together.
+      Specifying a column list has no effect on <literal>TRUNCATE</literal>
+      commands.
+     </para>

IMO you don't need to say "The column list and excluded column list
cannot be specified together." because AFAIK the syntax makes that
impossible to do anyhow.

~~~

8.
+  <para>
+   Create a publication that publishes all changes for table
<structname>users</structname>
+   except changes for columns <structname>security_pin</structname>:
+<programlisting>
+CREATE PUBLICATION users_safe FOR TABLE users EXCEPT (security_pin);
+</programlisting>
+  </para>

8a.
Same review comment as previously -- Those tags don't seem correct.
e.g. "users" and "security_pin" are not <structname> (???).
Again, are all the other existing tags also wrong? Maybe a new thread
needed to address these?

~

8b.
Plural?  /except changes for columns/except changes for column/

======
Kind Regards,
Peter Smith.
Fujitsu Australia