update documentation

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/trac439@3946 e5f2f494-b856-4b98-b285-d166d9295462

src/bin/auth/auth_srv.h

@@ -115,9 +115,11 @@ public:
     /// If there is a data source installed, it will be replaced with the
     /// new one.
     ///
-    /// In the current implementation, the SQLite data source is assumed.
-    /// The \c config parameter will simply be passed to the initialization
-    /// routine of the \c Sqlite3DataSrc class.
+    /// In the current implementation, the SQLite data source and MemoryDataSrc
+    /// are assumed.
+    /// We can enable memory data source and get the path of SQLite database by
+    /// the \c config parameter.  If we disabled memory data source, the SQLite
+    /// data source will be used.
     ///
     /// On success this method returns a data \c Element (in the form of a
     /// pointer like object) indicating the successful result,