From: Bruce Momjian <bruce@momjian.us>
Date: Tue, 26 Sep 2023 21:31:06 +0000 (-0400)
Subject: doc:  mention GROUP BY columns can reference target col numbers
X-Git-Tag: REL_12_17~65
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3d398ae4a5bb08ed146f94cedc4f4ca39dd8eed7;p=thirdparty%2Fpostgresql.git

doc:  mention GROUP BY columns can reference target col numbers

Reported-by: hape <postgres-hape@gmx.de>

Discussion: https://postgr.es/m/168871536004.379168.9352636188330923805@wrigleys.postgresql.org

Backpatch-through: 11
---

diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 1eb8cc04281..474ee23bf25 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -130,6 +130,9 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ]
       eliminates groups that do not satisfy the given condition.  (See
       <xref linkend="sql-groupby" endterm="sql-groupby-title"/> and
       <xref linkend="sql-having" endterm="sql-having-title"/> below.)
+      Although query output columns are nominally computed in the next
+      step, they can also be referenced (by name or ordinal number)
+      in the <literal>GROUP BY</literal> clause.
      </para>
     </listitem>