check_constraint_accross_table_note_v4.patch

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index b5ed1b7939..f57f6e716d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -403,6 +403,18 @@ CREATE TABLE products (
     ensure that a column does not contain null values, the not-null
     constraint described in the next section can be used.
    </para>
+
+   <note>
+    <para>
+     Postgres does not currently support CHECK constraints containing queries,
+     therefore we recommend to avoid them.  By using them, you may expect
+     troubles, especially to restore dumps.
+     CHECK constraints are currently meant to be used as row constraints only.
+     Use - if possible - UNIQUE or EXCLUDE constraints for constraints that
+     involve many or all rows of a table, and FOREIGN KEY constraints for cross
+     table constraints.
+    </para>
+   </note>
   </sect2>
 
   <sect2>