From d3e8368c4b6e5110d8b3d12859850aeaae08dffb Mon Sep 17 00:00:00 2001
From: Amit Kapila <akapila@postgresql.org>
Date: Tue, 8 Mar 2022 08:08:32 +0530
Subject: Add the additional information to the logical replication worker
 errcontext.

This commits adds both the finish LSN (commit_lsn in case transaction got
committed, prepare_lsn in case of a prepared transaction, etc.) and
replication origin name to the existing error context message.

This will help users in specifying the origin name and transaction finish
LSN to pg_replication_origin_advance() SQL function to skip a particular
transaction.

Author: Masahiko Sawada
Reviewed-by: Takamichi Osumi, Euler Taveira, and Amit Kapila
Discussion: https://postgr.es/m/CAD21AoBarBf2oTF71ig2g_o=3Z_Dt6_sOpMQma1kFgbnA5OZ_w@mail.gmail.com
---
 doc/src/sgml/logical-replication.sgml | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

(limited to 'doc/src')

diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml
index fb4472356d5..82326c39019 100644
--- a/doc/src/sgml/logical-replication.sgml
+++ b/doc/src/sgml/logical-replication.sgml
@@ -352,11 +352,26 @@
   <para>
    The resolution can be done either by changing data or permissions on the subscriber so
    that it does not conflict with the incoming change or by skipping the
-   transaction that conflicts with the existing data.  The transaction can be
-   skipped by calling the <link linkend="pg-replication-origin-advance">
+   transaction that conflicts with the existing data.  When a conflict produces
+   an error, the replication won't proceed, and the logical replication worker will
+   emit the following kind of message to the subscriber's server log:
+<screen>
+ERROR:  duplicate key value violates unique constraint "test_pkey"
+DETAIL:  Key (c)=(1) already exists.
+CONTEXT:  processing remote data for replication origin "pg_16395" during "INSERT" for replication target relation "public.test" in transaction 725 finished at 0/14C0378
+</screen>
+   The LSN of the transaction that contains the change violating the constraint and
+   the replication origin name can be found from the server log (LSN 0/14C0378 and
+   replication origin <literal>pg_16395</literal> in the above case).  To skip the
+   transaction, the subscription needs to be disabled temporarily by
+   <command>ALTER SUBSCRIPTION ... DISABLE</command> first. Then, the transaction
+   can be skipped by calling the
+   <link linkend="pg-replication-origin-advance">
    <function>pg_replication_origin_advance()</function></link> function with
-   a <parameter>node_name</parameter> corresponding to the subscription name,
-   and a position.  The current position of origins can be seen in the
+   the <parameter>node_name</parameter> (i.e., <literal>pg_16395</literal>) and the
+   next LSN of the transaction's LSN (i.e., LSN 0/14C0379).  After that the replication
+   can be resumed by <command>ALTER SUBSCRIPTION ... ENABLE</command>.  The current
+   position of origins can be seen in the
    <link linkend="view-pg-replication-origin-status">
    <structname>pg_replication_origin_status</structname></link> system view.
   </para>
-- 
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