RE: Handle infinite recursion in logical replication setup

On Tue, Sep 6, 2022 11:14 AM vignesh C <vignesh21(at)gmail(dot)com> wrote:
>
> Thanks for the comments, the attached patch has the changes for the same.
>

Thanks for updating the patch. Here are some comments.

1.
+ if (subrel_count)
+ {
+ /*
+ * In case of ALTER SUBSCRIPTION ... REFRESH, subrel_local_oids
+ * contains the list of relation oids that are already present on the
+ * subscriber. This check should be skipped for these tables.
+ */
+ appendStringInfo(&cmd, "AND C.oid NOT IN (\n"
+ "SELECT C.oid \n"
+ "FROM pg_class C\n"
+ " JOIN pg_namespace N ON N.oid = C.relnamespace\n"
+ "WHERE ");
+ get_skip_tables_str(subrel_local_oids, subrel_count, &cmd);
+ appendStringInfo(&cmd, ")");
+ }

I think we can skip the tables without using a subquery. See the SQL below.
Would it be better?

SELECT DISTINCT P.pubname AS pubname
FROM pg_publication P,
LATERAL pg_get_publication_tables(P.pubname) GPT
LEFT JOIN pg_subscription_rel PS ON (GPT.relid = PS.srrelid),
pg_class C JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE C.oid = GPT.relid AND PS.srrelid IS NOT NULL AND P.pubname IN ('p1', 'p3')
AND NOT (N.nspname = 'public' AND C.relname = 'tbl')
AND NOT (N.nspname = 'public' AND C.relname = 't1');

2.
+ When using a subscription parameter combination of
+ <literal>copy_data=true</literal> and <literal>origin=NONE</literal>, the

Could we use "copy_data = true" and "origin = NONE" (add two spaces around the
equals sign)? I think it looks clearer that way. And it is consistent with other
places in this file.

Regards,
Shi yu