0001-Doc-update.patch.txt

From c62d15d4127308fce79ec27ae30fe9ccc59a6132 Mon Sep 17 00:00:00 2001
From: Shveta Malik <shveta.malik@gmail.com>
Date: Mon, 6 Oct 2025 11:34:04 +0530
Subject: [PATCH] Doc update

---
 doc/src/sgml/logicaldecoding.sgml | 33 +++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/doc/src/sgml/logicaldecoding.sgml b/doc/src/sgml/logicaldecoding.sgml
index 504c79f2fd2..b964937d509 100644
--- a/doc/src/sgml/logicaldecoding.sgml
+++ b/doc/src/sgml/logicaldecoding.sgml
@@ -370,16 +370,12 @@ postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NU
      <function>pg_create_logical_replication_slot</function></link>, or by
      using the <link linkend="sql-createsubscription-params-with-failover">
      <literal>failover</literal></link> option of
-     <command>CREATE SUBSCRIPTION</command> during slot creation. After that,
-     synchronization can be performed either manually by calling
-     <link linkend="pg-sync-replication-slots">
-     <function>pg_sync_replication_slots</function></link>
-     on the standby, or automatically by enabling
-     <link linkend="guc-sync-replication-slots">
-     <varname>sync_replication_slots</varname></link> on the standby.
-     When <link linkend="guc-sync-replication-slots">
-     <varname>sync_replication_slots</varname></link> is enabled
-     on the standby, the failover slots are periodically synchronized by
+     <command>CREATE SUBSCRIPTION</command> during slot creation.
+     Additionally, enabling <link linkend="guc-sync-replication-slots">
+     <varname>sync_replication_slots</varname></link> on the standby
+     is required. By enabling <link linkend="guc-sync-replication-slots">
+     <varname>sync_replication_slots</varname></link>
+     on the standby, the failover slots can be synchronized periodically in
      the slotsync worker. For the synchronization to work, it is mandatory to
      have a physical replication slot between the primary and the standby (i.e.,
      <link linkend="guc-primary-slot-name"><varname>primary_slot_name</varname></link>
@@ -402,6 +398,23 @@ postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NU
      receiving the WAL up to the latest flushed position on the primary server.
     </para>
 
+    <note>
+     <para>
+      While enabling <link linkend="guc-sync-replication-slots">
+      <varname>sync_replication_slots</varname></link> allows for automatic
+      periodic synchronization of failover slots, they can also be manually
+      synchronized using the <link linkend="pg-sync-replication-slots">
+      <function>pg_sync_replication_slots</function></link> function on the standby.
+      However, unlike automatic synchronization, it does not perform incremental
+      updates. It retries cyclically to some extent—continuing until all
+      the failover slots that existed on primary at the start of the function
+      call are synchronized. Any slots created after the function begins will
+      not be synchronized. In contrast, automatic synchronization
+      via <varname>sync_replication_slots</varname> provides continuous slot
+      updates, enabling seamless failover and supporting high availability.
+     </para>
+    </note>
+
     <para>
      When slot synchronization is configured as recommended,
      and the initial synchronization is performed either automatically or
-- 
2.34.1