Improving Datastore Query performance

I use Restlet for my application Rest framework and Twist for Object mapping framework for GAE.

I installed Appstats servlet and filter to monitor my application performance when deployed live.

Here are the results for querying a set of "posts" as the app is loaded:

datastore_v3.RunQuery   121ms
RPC Total   121ms
Grand Total 1110ms

From my interpretation of this, it looks to be that the Object mapping and datastore query is quite fast or is fine. My concern is why the Grand Total is 1110ms, how is that? What is the thing that consumed 989 ms?