doc: New glossary entries

Add:

- "Restartpoint"
- "Log sequence number"

"LSN" was already listed in the Acronyms appendix, but it is more
suitable as a glossary entry, so move it there and have the acronyms
entry link into the glossary.

Also turn on DocBook parameter glossentry.show.acronym to show
acronyms for glossary entries, which is being used here.

Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/60915312-62cd-9c94-0d94-556023ece45f%40enterprisedb.com

doc/src/sgml/acronyms.sgml

@@ -402,8 +402,7 @@
     <term><acronym>LSN</acronym></term>
     <listitem>
      <para>
-      Log Sequence Number, see <link linkend="datatype-pg-lsn"><type>pg_lsn</type></link>
+      <glossterm linkend="glossary-log-sequence-number">Log Sequence Number</glossterm>
-      and <link linkend="wal-internals">WAL Internals</link>.
      </para>
     </listitem>
    </varlistentry>

doc/src/sgml/glossary.sgml

@@ -1039,6 +1039,28 @@
     </glossdef>
   </glossentry>
 
+  <glossentry id="glossary-log-sequence-number">
+   <glossterm>Log sequence number</glossterm>
+   <acronym>LSN</acronym>
+   <glossdef>
+    <para>
+     Byte offset into the <glossterm linkend="glossary-wal">WAL</glossterm>,
+     increasing monotonically with each new <glossterm
+     linkend="glossary-wal-record">WAL record</glossterm>.
+    </para>
+    <para>
+     For more information, see <link
+     linkend="datatype-pg-lsn"><type>pg_lsn</type></link> and <xref
+     linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>LSN</glossterm>
+   <glosssee otherterm="glossary-log-sequence-number"/>
+  </glossentry>
+
   <glossentry>
    <glossterm>Master (server)</glossterm>
    <glosssee otherterm="glossary-primary-server" />
@@ -1342,6 +1364,20 @@
    </glossdef>
   </glossentry>
 
+  <glossentry id="glossary-restartpoint">
+   <glossterm>Restartpoint</glossterm>
+   <glossdef>
+    <para>
+     A variant of a <glossterm
+     linkend="glossary-checkpoint">checkpoint</glossterm> performed on a
+     <glossterm linkend="glossary-replica">replica</glossterm>.
+    </para>
+    <para>
+     For more information, see <xref linkend="wal-configuration"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
   <glossentry id="glossary-result-set">
    <glossterm>Result set</glossterm>
    <glossdef>

doc/src/sgml/stylesheet-common.xsl

@@ -28,6 +28,7 @@
 </xsl:param>
 
 <xsl:param name="callout.graphics" select="'0'"></xsl:param>
+<xsl:param name="glossentry.show.acronym">yes</xsl:param>
 <xsl:param name="toc.section.depth">2</xsl:param>
 <xsl:param name="linenumbering.extension" select="'0'"></xsl:param>
 <xsl:param name="section.autolabel" select="1"></xsl:param>