Re: pgsql: Raise a warning if there is a possibility of data from multiple

On Thu, Sep 8, 2022 at 10:39 AM Amit Kapila <akapila@postgresql.org> wrote:
>
> Raise a warning if there is a possibility of data from multiple origins.
>
> This commit raises a warning message for a combination of options
> ('copy_data = true' and 'origin = none') during CREATE/ALTER subscription
> operations if the publication tables were also replicated from other
> publishers.
>
> During replication, we can skip the data from other origins as we have that
> information in WAL but that is not possible during initial sync so we raise
> a warning if there is such a possibility.
>
> Author: Vignesh C
> Reviewed-By: Peter Smith, Amit Kapila, Jonathan Katz, Shi yu, Wang wei
> Discussion: https://www.postgresql.org/message-id/CALDaNm0gwjY_4HFxvvty01BOT01q_fJLKQ3pWP9=9orqubhjcQ@mail.gmail.com
>
> Branch
> ------
> master
>
> Details
> -------
> https://git.postgresql.org/pg/commitdiff/875693019053b8897ec3983e292acbb439b088c3
>
> Modified Files
> --------------
> doc/src/sgml/ref/alter_subscription.sgml  |   5 ++
> doc/src/sgml/ref/create_subscription.sgml |  35 ++++++++
> src/backend/commands/subscriptioncmds.c   | 133 ++++++++++++++++++++++++++++--
> src/test/subscription/t/030_origin.pl     | 114 +++++++++++++++++++------
> 4 files changed, 258 insertions(+), 29 deletions(-)

+       appendStringInfoString(&cmd,
+                                                  "SELECT DISTINCT
P.pubname AS pubname\n"
+                                                  "FROM pg_publication P,\n"
+                                                  "     LATERAL
pg_get_publication_tables(P.pubname) GPT\n"
+                                                  "     JOIN
pg_subscription_rel PS ON (GPT.relid = PS.srrelid),\n"
+                                                  "     pg_class C
JOIN pg_namespace N ON (N.oid = C.relnamespace)\n"
+                                                  "WHERE C.oid =
GPT.relid AND P.pubname IN (");

Should the tables and the function in this query be schema-qualified?
Looking at other code in subscriptioncmd.c, we use schema-qualified
names. It works even without the schema names but it may be better to
make them consistent.

FYI, looking at tablesync.c, there are both styles; it seems that
recently added codes use schema-unqualified names.

Regards,

--
Masahiko Sawada