pg_upgrade doc: link mode additions

Mention that link mode uses less disk space, and uses junction points on
Windows.

Backpatch to 9.3.

diff --git a/doc/src/sgml/pgupgrade.sgml b/doc/src/sgml/pgupgrade.sgml
index c04e552bc93d29a39045f322d7758ecc99d9e40c..e38470a739f71867d2a0be63b9a24f3648510fdd 100644 (file)
--- a/doc/src/sgml/pgupgrade.sgml
+++ b/doc/src/sgml/pgupgrade.sgml
@@ -122,7 +122,8 @@
      <varlistentry>
       <term><option>-k</option></term>
       <term><option>--link</option></term>
-      <listitem><para>use hard links instead of copying files to the new cluster</para></listitem>
+      <listitem><para>use hard links instead of copying files to the new
+      cluster (use junction points on Windows)</para></listitem>
      </varlistentry>
 
      <varlistentry>
@@ -334,7 +335,8 @@ NET STOP pgsql-8.3  (<productname>PostgreSQL</> 8.3 and older used a different s
 
     <para>
      If you use link mode, the upgrade will be much faster (no file
-     copying), but you will not be able to access your old cluster
+     copying) and use less disk space, but you will not be able to access
+     your old cluster
      once you start the new cluster after the upgrade.  Link mode also
      requires that the old and new cluster data directories be in the
      same file system.  (Tablespaces and <filename>pg_xlog</> can be on