@@ -1281,7 +1281,8 @@ ROLLBACK TO s;
12811281
12821282 <caution>
12831283 <para>
1284- It is possible for a <command>SELECT</> command using <literal>ORDER
1284+ It is possible for a <command>SELECT</> command running at the <literal>READ
1285+ COMMITTED</literal> transaction isolation level and using <literal>ORDER
12851286 BY</literal> and <literal>FOR UPDATE/SHARE</literal> to return rows out of
12861287 order. This is because <literal>ORDER BY</> is applied first.
12871288 The command sorts the result, but might then block trying to obtain a lock
@@ -1302,6 +1303,13 @@ SELECT * FROM (SELECT * FROM mytable FOR UPDATE) ss ORDER BY column1;
13021303 only if concurrent updates of the ordering columns are expected and a
13031304 strictly sorted result is required.
13041305 </para>
1306+
1307+ <para>
1308+ At the <literal>REPEATABLE READ</literal> or <literal>SERIALIZABLE</literal>
1309+ transaction isolation level this would cause a serialization failure (with
1310+ a <literal>SQLSTATE</literal> of <literal>'40001'</literal>), so there is
1311+ no possibility of receiving rows out of order under these isolation levels.
1312+ </para>
13051313 </caution>
13061314 </refsect2>
13071315