From a5b75278a6dab39c5cd7a95a746c28ed8d5f1bbc Mon Sep 17 00:00:00 2001
From: amit <amitlangote09@gmail.com>
Date: Mon, 3 Apr 2017 16:45:15 +0900
Subject: [PATCH] Clarify that partition constraint is not enforced on foreign
 tables

---
 doc/src/sgml/ddl.sgml                      |  8 +++-----
 doc/src/sgml/ref/create_foreign_table.sgml | 17 +++++++++++------
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index b05a9c2150..a707c3e22a 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2986,11 +2986,9 @@ VALUES ('Albany', NULL, NULL, 'NY');
    </para>
 
    <para>
-    Partitions can also be foreign tables
-    (see <xref linkend="sql-createforeigntable">),
-    although these have some limitations that normal tables do not.  For
-    example, data inserted into the partitioned table is not routed to
-    foreign table partitions.
+    Partitions can also be foreign tables, although they have some limitations
+    that normal tables do not; see <xref linkend="sql-createforeigntable"> for
+    more information.
    </para>
 
    <sect3 id="ddl-partitioning-declarative-example">
diff --git a/doc/src/sgml/ref/create_foreign_table.sgml b/doc/src/sgml/ref/create_foreign_table.sgml
index 065c982082..594f75e112 100644
--- a/doc/src/sgml/ref/create_foreign_table.sgml
+++ b/doc/src/sgml/ref/create_foreign_table.sgml
@@ -79,7 +79,9 @@ CHECK ( <replaceable class="PARAMETER">expression</replaceable> ) [ NO INHERIT ]
   <para>
    If <literal>PARTITION OF</literal> clause is specified then the table is
    created as a partition of <literal>parent_table</literal> with specified
-   bounds.
+   bounds.  Note that routing tuples to partitions that are foreign tables
+   is not supported.  So, if a tuple inserted (or copied) into the table
+   routes to one of the foreign partitions, an error will occur.
   </para>
 
   <para>
@@ -279,16 +281,19 @@ CHECK ( <replaceable class="PARAMETER">expression</replaceable> ) [ NO INHERIT ]
   <title>Notes</title>
 
    <para>
-    Constraints on foreign tables (such as <literal>CHECK</>
-    or <literal>NOT NULL</> clauses) are not enforced by the
-    core <productname>PostgreSQL</> system, and most foreign data wrappers
-    do not attempt to enforce them either; that is, the constraint is
+    Constraints (both user-defined constraints, such as <literal>CHECK</>
+    or <literal>NOT NULL</> clauses, and the partition constraint) are not
+    enforced by the core <productname>PostgreSQL</> system, and most foreign
+    data wrappers do not attempt to enforce them either; that is, they are
     simply assumed to hold true.  There would be little point in such
     enforcement since it would only apply to rows inserted or updated via
     the foreign table, and not to rows modified by other means, such as
     directly on the remote server.  Instead, a constraint attached to a
     foreign table should represent a constraint that is being enforced by
-    the remote server.
+    the remote server.  That becomes especially important if the table is
+    being used in a partition hierarchy, where it is recommended to add
+    a constraint matching the partition constraint expression on
+    the remote table.
    </para>
 
    <para>
-- 
2.11.0