1 files changed, 43 insertions, 1 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 528197e4bcc..34c5c2a2d6b 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -13278,7 +13278,7 @@ select $1[i][j]
         generate_subscripts($1,2) g2(j);
 $$ LANGUAGE sql IMMUTABLE;
 CREATE FUNCTION
-postgres=# SELECT * FROM unnest2(ARRAY[[1,2],[3,4]]);
+SELECT * FROM unnest2(ARRAY[[1,2],[3,4]]);
  unnest2 
 ---------
        1
@@ -13289,6 +13289,48 @@ postgres=# SELECT * FROM unnest2(ARRAY[[1,2],[3,4]]);
 </programlisting>
   </para>
 
+  <indexterm>
+   <primary>ordinality</primary>
+  </indexterm>
+
+  <para>
+  When a function in the <literal>FROM</literal> clause is suffixed by
+  <literal>WITH ORDINALITY</literal>, a <type>bigint</type> column is appended
+  to the output which starts from 1 and increments by 1 for each row of the
+  function's output.  This is most useful in the case of set returning functions
+  such as UNNEST(). This functionality is available for functions returning
+  composite types or using <literal>OUT</literal> parameters, but not when using
+  a function returning <literal>RECORD</literal> with an explicit column
+  definition list.
+
+<programlisting>
+-- set returning function WITH ORDINALITY
+SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n);
+       ls        | n  
+-----------------+----
+ pg_serial       |  1
+ pg_twophase     |  2
+ postmaster.opts |  3
+ pg_notify       |  4
+ postgresql.conf |  5
+ pg_tblspc       |  6
+ logfile         |  7
+ base            |  8
+ postmaster.pid  |  9
+ pg_ident.conf   | 10
+ global          | 11
+ pg_clog         | 12
+ pg_snapshots    | 13
+ pg_multixact    | 14
+ PG_VERSION      | 15
+ pg_xlog         | 16
+ pg_hba.conf     | 17
+ pg_stat_tmp     | 18
+ pg_subtrans     | 19
+(19 rows)
+</programlisting>
+  </para>
+
  </sect1>
 
  <sect1 id="functions-info">