Re: CREATE EXTENSION BLOCKS

"David E. Wheeler" <david@justatheory.com> writes:
> On Apr 3, 2013, at 11:41 AM, Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
>> Right -- an extension is not considered to live within a schema, they
>> are database-global.  The objects might live in a particular schema (if
>> it is "relocatable"), and there's support to move those to a different
>> schema, but this doesn't affect the extension itself.

> Thanks. I humbly submit this patch to help prevent silly questions like this in the future.

I think this should be addressed in extend.sgml not only on the CREATE
EXTENSION reference page.  After thinking awhile I came up with the
attached wording.  Further wordsmithing anyone?

            regards, tom lane

diff --git a/doc/src/sgml/extend.sgml b/doc/src/sgml/extend.sgml
index 672d0df..bc1cd59 100644
*** a/doc/src/sgml/extend.sgml
--- b/doc/src/sgml/extend.sgml
***************
*** 359,364 ****
--- 359,370 ----
      extension.)  Also notice that while a table can be a member of an
      extension, its subsidiary objects such as indexes are not directly
      considered members of the extension.
+     Another important point is that schemas can belong to extensions, but not
+     vice versa: an extension as such has an unqualified name and does not
+     exist <quote>within</> any schema.  The extension's member objects,
+     however, will belong to schemas whenever appropriate for their object
+     types.  It may or may not be appropriate for an extension to own the
+     schema(s) its member objects are within.
     </para>

     <sect2>
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index 4f3b9a5..9c9bf6f 100644
*** a/doc/src/sgml/ref/create_extension.sgml
--- b/doc/src/sgml/ref/create_extension.sgml
*************** CREATE EXTENSION [ IF NOT EXISTS ] <repl
*** 94,99 ****
--- 94,105 ----
          If not specified, and the extension's control file does not specify a
          schema either, the current default object creation schema is used.
         </para>
+        <para>
+         Remember that the extension itself is not considered to be within any
+         schema: extensions have unqualified names that must be unique
+         database-wide.  But objects belonging to the extension can be within
+         schemas.
+        </para>
        </listitem>
       </varlistentry>