Documented new DemoStorage and MappingStorage features.

Moved size-limiting-cache feature to future release, since it

src/CHANGES.txt

@@ -2,12 +2,41 @@
  Change History
 ================
 
-3.9.0a1 (2008-??-??)
+3.9.0a2 (2008-??-??)
+====================
+
+- The connection now estimates the object size based on its pickle size
+  and informs the cache about size changes.
+
+  The database got additional configurations options (`cache-size-bytes`
+  and `historical-cache-size-bytes`) to limit the
+  cache size based on the estimated total size of cached objects.
+  The default values are 0 which has the interpretation "do not limit
+  based on the total estimated size".
+  There are corresponding methods to read and set the new configuration
+  parameters.
+
+  XXX There are known issues with this implementation that need to be
+  sorted out before it is "released".
+
+3.9.0a1 (2008-10-29)
 ====================
 
 New Features
 ------------
 
+- MappingStorage now supports multi-version concurrency control and
+  iteration and provides a better storage implementation example.
+
+- DemoStorage has a number of new features:
+
+  - The ability to use a separate storage, such as a file storage to
+    store changes
+
+  - Blob support
+
+  - Multi-version concurrency control and iteration
+
 - Wen calling ZODB.DB to create a database, you can now pass a file
   name, rather than a storage to use a file storage.
 
@@ -34,17 +63,6 @@ New Features
   option can avoid effective downtimes in the order of hours when
   the connection to the ZEO server was interrupted for a longer time.
 
-- The connection now estimates the object size based on its pickle size
-  and informs the cache about size changes.
-
-  The database got additional configurations options (`cache-size-bytes`
-  and `historical-cache-size-bytes`) to limit the
-  cache size based on the estimated total size of cached objects.
-  The default values are 0 which has the interpretation "do not limit
-  based on the total estimated size".
-  There are corresponding methods to read and set the new configuration
-  parameters.
-
 - Cleaned-up the storage iteration API and provided an iterator implementation
   for ZEO.