column_name of ALTER MATERIALIZED VIEW should only refer to an existing column

[Erik Wienhold]

Here's a patch for $SUBJECT.  Looks like the current wording was copied
from ALTER TABLE.  In ALTER VIEW we correctly state that column_name
must be an existing column.

-- 
Erik

>From 1d7accf2311f4fda2d8ef9a0485985620c5b4b39 Mon Sep 17 00:00:00 2001
From: Erik Wienhold <e...@ewie.name>
Date: Wed, 22 May 2024 02:30:16 +0200
Subject: [PATCH] doc: fix column_name parameter in ALTER MATERIALIZED VIEW

Parameter column_name must be an existing column because ALTER
MATERIALIZED VIEW cannot add new columns.  The old description was
likely copied from ALTER TABLE.
---
 doc/src/sgml/ref/alter_materialized_view.sgml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/src/sgml/ref/alter_materialized_view.sgml b/doc/src/sgml/ref/alter_materialized_view.sgml
index da7ed04597..f81a7393f5 100644
--- a/doc/src/sgml/ref/alter_materialized_view.sgml
+++ b/doc/src/sgml/ref/alter_materialized_view.sgml
@@ -100,7 +100,7 @@ ALTER MATERIALIZED VIEW ALL IN TABLESPACE <replaceable class="parameter">name</r
      <term><replaceable class="parameter">column_name</replaceable></term>
      <listitem>
       <para>
-       Name of a new or existing column.
+       Name of an existing column.
       </para>
      </listitem>
     </varlistentry>
-- 
2.45.1