Another round of editorialization on the text search documentation.

Notably, standardize on using "token" for the strings output by a parser,
while "lexeme" is reserved for the normalized strings produced by a
dictionary.

doc/src/sgml/ref/alter_tsdictionary.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/alter_tsdictionary.sgml,v 1.2 2007/08/22 01:39:44 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/alter_tsdictionary.sgml,v 1.3 2007/10/17 01:01:28 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -122,6 +122,21 @@ ALTER TEXT SEARCH DICTIONARY my_dict ( StopWords = newrussian );
 <programlisting>
 ALTER TEXT SEARCH DICTIONARY my_dict ( language = dutch, StopWords );
 </programlisting>  
+
+  <para>
+   The following example command <quote>updates</> the dictionary's
+   definition without actually changing anything.
+
+<programlisting>
+ALTER TEXT SEARCH DICTIONARY my_dict ( dummy );
+</programlisting>
+
+   (The reason this works is that the option removal code doesn't complain
+   if there is no such option.)  This trick is useful when changing
+   configuration files for the dictionary: the <command>ALTER</> will
+   force existing database sessions to re-read the configuration files,
+   which otherwise they would never do if they had read them earlier.
+  </para>
  </refsect1>
 
  <refsect1>