Implement an API to let foreign-data wrappers actually be functional.

This commit provides the core code and documentation needed.  A contrib
module test case will follow shortly.

Shigeru Hanada, Jan Urbanski, Heikki Linnakangas

2 files changed, 6 insertions, 11 deletions

diff --git a/doc/src/sgml/ref/create_foreign_data_wrapper.sgml b/doc/src/sgml/ref/create_foreign_data_wrapper.sgml
index 711f32b118b..3093ebcb4ac 100644
--- a/doc/src/sgml/ref/create_foreign_data_wrapper.sgml
+++ b/doc/src/sgml/ref/create_foreign_data_wrapper.sgml
@@ -119,18 +119,13 @@ CREATE FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable>
   <title>Notes</title>
 
   <para>
-   At the moment, the foreign-data wrapper functionality is very
-   rudimentary.  The purpose of foreign-data wrappers, foreign
-   servers, and user mappings is to store this information in a
-   standard way so that it can be queried by interested applications.
-   One such application is <application>dblink</application>;
-   see <xref linkend="dblink">.  The functionality to actually query
-   external data through a foreign-data wrapper library does not exist
-   yet.
+   At the moment, the foreign-data wrapper functionality is rudimentary.
+   There is no support for updating a foreign table, and optimization of
+   queries is primitive (and mostly left to the wrapper, too).
   </para>
 
   <para>
-   There is currently one foreign-data wrapper validator function
+   There is one built-in foreign-data wrapper validator function
    provided:
    <filename>postgresql_fdw_validator</filename>, which accepts
    options corresponding to <application>libpq</> connection
diff --git a/doc/src/sgml/ref/create_foreign_table.sgml b/doc/src/sgml/ref/create_foreign_table.sgml
index ac2e1393e38..77c62140f28 100644
--- a/doc/src/sgml/ref/create_foreign_table.sgml
+++ b/doc/src/sgml/ref/create_foreign_table.sgml
@@ -131,8 +131,8 @@ CREATE FOREIGN TABLE [ IF NOT EXISTS ] <replaceable class="PARAMETER">table_name
      <para>
       Options to be associated with the new foreign table.
       The allowed option names and values are specific to each foreign
-      data wrapper and are validated using the foreign-data wrapper
-      library. Option names must be unique. 
+      data wrapper and are validated using the foreign-data wrapper's
+      validator function. Option names must be unique.
      </para>
     </listitem>
    </varlistentry>