-<!-- $PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.125 2008/10/29 14:35:04 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.126 2008/12/09 20:52:03 tgl Exp $ -->
<chapter id="sql-syntax">
<title>SQL Syntax</title>
</programlisting>
(Thus, a qualified column reference is actually just a special case
- of the field selection syntax.)
+ of the field selection syntax.) An important special case is
+ extracting a field from a table column that is of a composite type:
+
+<programlisting>
+(compositecol).somefield
+(mytable.compositecol).somefield
+</programlisting>
+
+ The parentheses are required here to show that
+ <structfield>compositecol</> is a column name not a table name,
+ or that <structname>mytable</> is a table name not a schema name
+ in the second case.
</para>
</sect2>