Re: Skipping logical replication transactions on subscriber side

On Tue, Oct 12, 2021 at 4:00 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> I've attached updated patches.
>

Some comments for the v16-0003 patch:

(1) doc/src/sgml/logical-replication.sgml

The output from "SELECT * FROM pg_stat_subscription_errors;" still
shows "last_failed_time" instead of "last_error_time".

doc/src/sgml/ref/alter_subscription.sgml
(2)

Suggested update (and fix typo: restrited -> restricted):

BEFORE:
+          Setting and resetting of <literal>skip_xid</literal> option is
+          restrited to superusers.
AFTER:
+          The setting and resetting of the
<literal>skip_xid</literal> option is
+          restricted to superusers.

(3)
Suggested improvement to the wording:

BEFORE:
+          incoming change or by skipping the whole transaction.  This option
+          specifies transaction ID that logical replication worker skips to
+          apply.  The logical replication worker skips all data modification
AFTER:
+          incoming changes or by skipping the whole transaction.  This option
+          specifies the ID of the transaction whose application is to
be skipped
+          by the logical replication worker. The logical replication worker
+          skips all data modification

(4) src/backend/replication/logical/worker.c

Suggested improvement to the comment wording:

BEFORE:
+ * Stop the skipping transaction if enabled. Otherwise, commit the changes
AFTER:
+ * Stop skipping the transaction changes, if enabled. Otherwise,
commit the changes


(5) skip_xid value validation

The validation of the specified skip_xid XID value isn't great.
For example, the following value are accepted:

    ALTER SUBSCRIPTION sub SET (skip_xid='123abcz');
    ALTER SUBSCRIPTION sub SET (skip_xid='99$@*');


Regards,
Greg Nancarrow
Fujitsu Australia