doc: Add an example of REPACK (CONCURRENTLY)

Suggested-by: vignesh C <vignesh21@gmail.com>
Discussion: https://postgr.es/m/CALDaNm3tiKhtegx5Cawi34UjbHmNGEDNAtScGM1RgWRtV-5_0Q@mail.gmail.com

diff --git a/doc/src/sgml/ref/repack.sgml b/doc/src/sgml/ref/repack.sgml
index e993dfb31086d7ccfcac0d3f49f6c322efe92ffe..ac020406d11436325060a480e6d5b9d26970a291 100644 (file)
--- a/doc/src/sgml/ref/repack.sgml
+++ b/doc/src/sgml/ref/repack.sgml
@@ -390,13 +390,21 @@ REPACK employees;
 
   <para>
    Repack the table <literal>employees</literal> on the basis of its
-   index <literal>employees_ind</literal> (Since index is used here, this is
+   index <literal>employees_ind</literal> (since an index is specified, this is
    effectively clustering):
 <programlisting>
 REPACK employees USING INDEX employees_ind;
 </programlisting>
   </para>
 
+  <para>
+   Repack the <literal>employees</literal> table following the same index
+   as was used before, in concurrent mode:
+<programlisting>
+REPACK (CONCURRENTLY) employees USING INDEX;
+</programlisting>
+  </para>
+
   <para>
    Repack the table <literal>cases</literal> on physical ordering,
    running an <command>ANALYZE</command> on the given columns once