Add some useful cross-references to the CREATE EXTENSION reference page.

Per a suggestion from Josh Kupershmidt, though I modified his patch
quite a lot.

diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index 818bc0c4b48d5f65c15e2a88f7e235a13ab66be0..7670d76f8944216ab38dba62a5c650744ef3d3db 100644 (file)
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -45,11 +45,6 @@ CREATE EXTENSION [ IF NOT EXISTS ] extension_name
    DROP EXTENSION is issued.
   
 
-  
-   For information about writing new extensions, see
-   .
-  
-
   
    Loading an extension requires the same privileges that would be
    required to create its component objects.  For most extensions this
@@ -72,7 +67,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] extension_name
         Do not throw an error if an extension with the same name already
         exists.  A notice is issued in this case.  Note that there is no
         guarantee that the existing extension is anything like the one that
-        would have been created.
+        would have been created from the currently-available script file.
        
       
      
@@ -142,6 +137,31 @@ CREATE EXTENSION [ IF NOT EXISTS ] extension_name
   
  
 
+ 
+  Notes
+
+  
+   Before you can use CREATE EXTENSION to load an extension
+   into a database, the extension's supporting files must be installed.
+   Information about installing the extensions supplied with
+   PostgreSQL can be found in
+   Additional Supplied Modules.
+  
+
+  
+   The extensions currently available for loading can be identified from the
+   pg_available_extensions
+   or
+   pg_available_extension_versions
+   system views.
+  
+
+  
+   For information about writing new extensions, see
+   .
+  
+ 
+
  
   Examples