Add missing rst file.

doc/source/database.rst

@@ -0,0 +1,24 @@
+..
+      Copyright 2010 United States Government as represented by the
+      Administrator of the National Aeronautics and Space Administration. 
+      All Rights Reserved.
+
+      Licensed under the Apache License, Version 2.0 (the "License"); you may
+      not use this file except in compliance with the License. You may obtain
+      a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
+      distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+      WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+      License for the specific language governing permissions and limitations
+      under the License.
+
+Nova Database Programming Guide
+===============================
+
+::
+
+    * general interface
+    * sqlalchemy implementation