[CF 5111] v20251111 - Synchronization of sequences to subscriber

This branch was automatically generated by a robot using patches from an
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https://commitfest.postgresql.org/patch/5111

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Patch(es): https://www.postgresql.org/message-id/CALDaNm0zHQaUpXRtXKR90esaR9o180ejxzQ=+_R=LSmyrDu52Q@mail.gmail.com
Author(s): vigneshwaran C

Author: Commitfest Bot

doc/src/sgml/catalogs.sgml

@@ -6568,7 +6568,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
        (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>oid</structfield>)
       </para>
       <para>
-       Reference to relation
+       Reference to table or sequence
       </para></entry>
      </row>
 

doc/src/sgml/config.sgml

@@ -5198,9 +5198,9 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
         is taken into account.
        </para>
        <para>
-        In logical replication, this parameter also limits how often a failing
-        replication apply worker or table synchronization worker will be
-        respawned.
+        In logical replication, this parameter also limits how quickly a
+        failing replication apply worker or table/sequence synchronization
+        worker will be respawned.
        </para>
       </listitem>
      </varlistentry>
@@ -5341,8 +5341,8 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
       <listitem>
        <para>
         Specifies maximum number of logical replication workers. This includes
-        leader apply workers, parallel apply workers, and table synchronization
-        workers.
+        leader apply workers, parallel apply workers, and table/sequence
+        synchronization workers.
        </para>
        <para>
         Logical replication workers are taken from the pool defined by
@@ -5365,10 +5365,14 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
        <para>
         Maximum number of synchronization workers per subscription. This
         parameter controls the amount of parallelism of the initial data copy
-        during the subscription initialization or when new tables are added.
+        for tables during the subscription initialization or when new tables
+        are added. One additional worker is also needed for sequence
+        synchronization.
        </para>
        <para>
-        Currently, there can be only one synchronization worker per table.
+        Currently, there can be only one table synchronization worker per table
+        and one sequence synchronization worker to synchronize per
+        subscription.
        </para>
        <para>
         The synchronization workers are taken from the pool defined by

doc/src/sgml/func/func-sequence.sgml

@@ -67,15 +67,15 @@
        </para>
        <para>
         Sets the sequence object's current value, and optionally
-        its <literal>is_called</literal> flag.  The two-parameter
-        form sets the sequence's <literal>last_value</literal> field to the
-        specified value and sets its <literal>is_called</literal> field to
-        <literal>true</literal>, meaning that the next
+        its <structfield>is_called</structfield> flag.  The two-parameter
+        form sets the sequence's <structfield>last_value</structfield> field to
+        the specified value and sets its <structfield>is_called</structfield>
+        field to <literal>true</literal>, meaning that the next
         <function>nextval</function> will advance the sequence before
         returning a value.  The value that will be reported
         by <function>currval</function> is also set to the specified value.
-        In the three-parameter form, <literal>is_called</literal> can be set
-        to either <literal>true</literal>
+        In the three-parameter form, <structfield>is_called</structfield> can
+        be set to either <literal>true</literal>
         or <literal>false</literal>.  <literal>true</literal> has the same
         effect as the two-parameter form. If it is set
         to <literal>false</literal>, the next <function>nextval</function>
@@ -143,6 +143,33 @@ SELECT setval('myseq', 42, false);    <lineannotation>Next <function>nextval</fu
         or <literal>SELECT</literal> privilege on the last used sequence.
        </para></entry>
       </row>
+
+      <row>
+       <entry role="func_table_entry" id="func-pg-get-sequence-data"><para role="func_signature">
+        <indexterm>
+         <primary>pg_get_sequence_data</primary>
+        </indexterm>
+        <function>pg_get_sequence_data</function> ( <type>regclass</type> )
+        <returnvalue>record</returnvalue>
+        ( <parameter>last_value</parameter> <type>bigint</type>,
+        <parameter>is_called</parameter> <type>bool</type>,
+         <parameter>page_lsn</parameter> <type>pg_lsn</type> )
+       </para>
+       <para>
+        Returns information about the sequence.
+        <structfield>last_value</structfield> is primarily intended for
+        internal use by pg_dump and by logical replication to synchronize
+        sequences. <structfield>is_called</structfield> indicates whether the
+        sequence has been used. Logical replication's sequence synchronization
+        updates the subscriber's sequence values to match the publisher's.
+        <structfield>page_lsn</structfield> is the LSN corresponding to the
+        most recent WAL record that modified this sequence relation.
+       </para>
+       <para>
+        This function requires <literal>USAGE</literal>
+        or <literal>SELECT</literal> privilege on the sequence.
+       </para></entry>
+      </row>
      </tbody>
     </tgroup>
    </table>