Horton

Re: Skipping schema changes in publication

shveta malik <shveta.malik@gmail.com>

View thread
From: shveta malik <shveta.malik@gmail.com>
To: Shlok Kyal <shlok.kyal.oss@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, vignesh C <vignesh21@gmail.com>, YeXiu <1518981153@qq.com>, Ian Lawrence Barwick <barwick@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, shveta malik <shveta.malik@gmail.com>
Date: 2025-06-26T09:57:36Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix miscellaneous issues in EXCEPT publication clause.

  2. Change syntax of EXCEPT TABLE clause in publication commands.

  3. Add support for EXCEPT TABLE in ALTER PUBLICATION.

  4. Allow table exclusions in publications via EXCEPT TABLE.

  5. Add wait_for_subscription_sync for TAP tests.

On Tue, Jun 24, 2025 at 9:48 AM Shlok Kyal <shlok.kyal.oss@gmail.com> wrote:
>
>  I have included the changes for
> it in v14-0003 patch.
>
Thanks for the patches. I have reviewed patch001 alone, please find
few comments:

1)
+  <para>
+   The <literal>RESET</literal> clause will reset the publication to the
+   default state which includes resetting the publication parameters, setting
+   <literal>ALL TABLES</literal> flag to <literal>false</literal> and
+   dropping all relations and schemas that are associated with the
+   publication.
   </para>

It is misleading, as far as I have understood, we do not drop the
tables or schemas associated with the pub; we just remove those from
the publication's object list. See previous doc:
"The ADD and DROP clauses will add and remove one or more
tables/schemas from the publication"

Perhaps we want to say the same thing when we speak about the 'drop'
aspect of RESET.

2)
AlterPublicationReset():

+ if (!OidIsValid(prid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("relation \"%s\" is not part of the publication",
+ get_rel_name(relid))));

Can you please help me understand which scenario will give this error?

Another question is do we really need this error? IIUC, we generally
give errors if a user has explicitly called out a name of an object
and that object is not found. Example:

postgres=# alter publication pubnew drop table t1,tab2;
ERROR:  relation "t1" is not part of the publication

While in a few other cases, we pass missing_okay as true and do not
give errors. Please see other callers of performDeletion in
publicationcmds.c itself. There we have usage of missing_okay=true. I
have not researched myself, but please analyze the cases where
missing_okay is passed as true to figure out if those match our RESET
case. Try to reproduce if possible and then take a call.

3)
+ALTER PUBLICATION testpub_reset ADD ALL TABLES IN SCHEMA public;
+ERROR:  syntax error at or near "ALL"
+LINE 1: ALTER PUBLICATION testpub_reset ADD ALL TABLES IN SCHEMA pub...

There is a problem in syntax, I think the intention of testcase was to
run this query successfully.

thanks
Shveta