v39-0008-Documentation-patch.patch
application/octet-stream
Filename: v39-0008-Documentation-patch.patch
Type: application/octet-stream
Part: 7
From a86e283d20d30ddc72e862cac89b5323d2bb2885 Mon Sep 17 00:00:00 2001
From: Dilip Kumar <dilipkumar@Dilip.local>
Date: Sun, 5 Apr 2026 17:02:01 +0530
Subject: [PATCH v39 08/10] Documentation patch
---
doc/src/sgml/logical-replication.sgml | 114 +++++++++++++++++++++-
doc/src/sgml/ref/alter_subscription.sgml | 13 ++-
doc/src/sgml/ref/create_subscription.sgml | 47 +++++++++
3 files changed, 171 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml
index 9e7868487de..572e0d45383 100644
--- a/doc/src/sgml/logical-replication.sgml
+++ b/doc/src/sgml/logical-replication.sgml
@@ -293,6 +293,19 @@
option of <command>CREATE SUBSCRIPTION</command> for details.
</para>
+ <para>
+ Conflicts that occur during replication are, by default, logged as plain text
+ in the server log, which can make automated monitoring and analysis difficult.
+ The <command>CREATE SUBSCRIPTION</command> command provides the
+ <link linkend="sql-createsubscription-params-with-conflict-log-destination">
+ <literal>conflict_log_destination</literal></link> option to record detailed
+ conflict information in a structured, queryable format. When this parameter
+ is set to <literal>table</literal> or <literal>all</literal>, the system
+ automatically manages a dedicated conflict log table, which is created and
+ dropped along with the subscription. This significantly improves post-mortem
+ analysis and operational visibility of the replication setup.
+ </para>
+
<sect2 id="logical-replication-subscription-slot">
<title>Logical Replication Slot Management</title>
@@ -2122,7 +2135,99 @@ Included in publications:
</para>
<para>
- The log format for logical replication conflicts is as follows:
+ The <link linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link>
+ parameter automatically creates a dedicated conflict log table. This table is created in the dedicated
+ <literal>pg_conflict</literal> namespace. The name of the conflict log table
+ is <literal>pg_conflict_log_<subid></literal>. The predefined schema of this table is
+ detailed in
+ <xref linkend="logical-replication-conflict-log-schema"/>.
+ </para>
+
+ <table id="logical-replication-conflict-log-schema">
+ <title>Conflict Log Table Schema</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>Column</entry>
+ <entry>Type</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry><literal>relid</literal></entry>
+ <entry><type>oid</type></entry>
+ <entry>The OID of the local table where the conflict occurred.</entry>
+ </row>
+ <row>
+ <entry><literal>schemaname</literal></entry>
+ <entry><type>text</type></entry>
+ <entry>The schema name of the conflicting table.</entry>
+ </row>
+ <row>
+ <entry><literal>relname</literal></entry>
+ <entry><type>text</type></entry>
+ <entry>The name of the conflicting table.</entry>
+ </row>
+ <row>
+ <entry><literal>conflict_type</literal></entry>
+ <entry><type>text</type></entry>
+ <entry>The type of conflict that occurred (e.g., <literal>insert_exists</literal>).</entry>
+ </row>
+ <row>
+ <entry><literal>remote_xid</literal></entry>
+ <entry><type>xid</type></entry>
+ <entry>The remote transaction ID that caused the conflict.</entry>
+ </row>
+ <row>
+ <entry><literal>remote_commit_lsn</literal></entry>
+ <entry><type>pg_lsn</type></entry>
+ <entry>The final LSN of the remote transaction.</entry>
+ </row>
+ <row>
+ <entry><literal>remote_commit_ts</literal></entry>
+ <entry><type>timestamptz</type></entry>
+ <entry>The remote commit timestamp of the remote transaction.</entry>
+ </row>
+ <row>
+ <entry><literal>remote_origin</literal></entry>
+ <entry><type>text</type></entry>
+ <entry>The origin of the remote transaction.</entry>
+ </row>
+ <row>
+ <entry><literal>replica_identity</literal></entry>
+ <entry><type>json</type></entry>
+ <entry>The JSON representation of the replica identity.</entry>
+ </row>
+ <row>
+ <entry><literal>remote_tuple</literal></entry>
+ <entry><type>json</type></entry>
+ <entry>The JSON representation of the incoming remote row that caused the conflict.</entry>
+ </row>
+ <row>
+ <entry><literal>local_conflicts</literal></entry>
+ <entry><type>json[]</type></entry>
+ <entry>
+ An array of JSON objects representing the local state for each conflict attempt.
+ Each object includes the local transaction ID (<literal>xid</literal>), commit
+ timestamp (<literal>commit_ts</literal>), origin (<literal>origin</literal>),
+ conflicting key data (<literal>key</literal>), and the full local row
+ image (<literal>tuple</literal>).
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <para>
+ The conflicting row data, including the incoming remote row (<literal>remote_tuple</literal>)
+ and the associated local conflict details (<literal>local_conflicts</literal>), is stored in
+ <type>JSON</type> formats, for flexible querying and analysis.
+ </para>
+
+ <para>
+ If <link linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link>
+ is set to log conflicts to the server log, the following format is used:
<synopsis>
LOG: conflict detected on relation "<replaceable>schemaname</replaceable>.<replaceable>tablename</replaceable>": conflict=<replaceable>conflict_type</replaceable>
DETAIL: <replaceable class="parameter">detailed_explanation</replaceable>[: <replaceable class="parameter">detail_values</replaceable> [, ... ]].
@@ -2415,6 +2520,13 @@ CONTEXT: processing remote data for replication origin "pg_16395" during "INSER
key or replica identity defined for it.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Conflict log tables (see <link linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link> parameter)
+ are never published, even when using FOR ALL TABLES in a publication.
+ </para>
+ </listitem>
</itemizedlist>
</sect1>
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index e4f0b6b16c7..07b7ede52ec 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -293,8 +293,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>,
<link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>,
<link linkend="sql-createsubscription-params-with-retain-dead-tuples"><literal>retain_dead_tuples</literal></link>,
- <link linkend="sql-createsubscription-params-with-max-retention-duration"><literal>max_retention_duration</literal></link>, and
- <link linkend="sql-createsubscription-params-with-wal-receiver-timeout"><literal>wal_receiver_timeout</literal></link>.
+ <link linkend="sql-createsubscription-params-with-max-retention-duration"><literal>max_retention_duration</literal></link>,
+ <link linkend="sql-createsubscription-params-with-wal-receiver-timeout"><literal>wal_receiver_timeout</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
</para>
@@ -352,6 +353,14 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<quote><literal>pg_conflict_detection</literal></quote>, created to retain
dead tuples for conflict detection, will be dropped.
</para>
+
+ <para>
+ When the <link linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link>
+ parameter is set to <literal>table</literal> or <literal>all</literal>, the system
+ automatically creates the internal conflict log table. Conversely, if the destination is changed to
+ <literal>log</literal>, logging to the table stops and the internal
+ table is automatically dropped.
+ </para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml
index 07d5b1bd77c..7fb11f31b21 100644
--- a/doc/src/sgml/ref/create_subscription.sgml
+++ b/doc/src/sgml/ref/create_subscription.sgml
@@ -261,6 +261,53 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
</listitem>
</varlistentry>
+ <varlistentry id="sql-createsubscription-params-with-conflict-log-destination">
+ <term><literal>conflict_log_destination</literal> (<type>enum</type>)</term>
+ <listitem>
+ <para>
+ Specifies the destination for recording logical replication conflicts.
+ </para>
+ <para>
+ The available destinations are:
+ <itemizedlist>
+ <listitem>
+ <para>
+ <literal>log</literal>: Conflict details are recorded in the server log.
+ This is the default behavior.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <literal>table</literal>: The system automatically creates a structured table
+ named <literal>pg_conflict_log_<subid></literal> in the
+ <literal>pg_conflict</literal> schema. This allows for easy querying and
+ analysis of conflicts.
+ </para>
+ <caution>
+ <para>
+ The internal conflict log table is strictly tied to the lifecycle of the
+ subscription or the <literal>conflict_log_destination</literal> setting. If
+ the subscription is dropped, or if the destination is changed to
+ <literal>log</literal>, the table and all its recorded conflict data are
+ <emphasis>permanently deleted</emphasis>.
+ </para>
+ <para>
+ If post-mortem analysis may be needed, back up the conflict log table before
+ removing the subscription.
+ </para>
+ </caution>
+ </listitem>
+ <listitem>
+ <para>
+ <literal>all</literal>: Records conflict details to both destinations
+ <literal>log</literal> and <literal>table</literal>.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createsubscription-params-with-copy-data">
<term><literal>copy_data</literal> (<type>boolean</type>)</term>
<listitem>
--
2.53.0