<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.83 2005/04/08 00:59:58 neilc Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.84 2005/04/22 04:20:44 momjian Exp $
PostgreSQL documentation
-->
</para>
<para>
- <literal>FOR UPDATE</literal> may appear before
- <literal>LIMIT</literal> for compatibility with
- <productname>PostgreSQL</productname> versions before 7.3. It
- effectively executes after <literal>LIMIT</literal>, however, and
- so that is the recommended place to write it.
+ It is possible for a <command>SELECT</> command using both
+ <literal>LIMIT</literal> and <literal>FOR UPDATE</literal>
+ clauses to return fewer rows than specified by <literal>LIMIT</literal>.
+ This is because <literal>LIMIT</> selects a number of rows,
+ but might then block requesting a <literal>FOR UPDATE</literal> lock.
+ Once the <literal>SELECT</> unblocks, the query qualifiation might not
+ be met and the row not be returned by <literal>SELECT</>.
</para>
</refsect2>
</refsect1>