I'm doing some queries using the new Rally Lookback API and am wondering what is the Lookback API analog to story counting REST request in traditional Rally webservices that is discussed in this question:
This will return all of the ObjectIDs of all of the defects for a particular story:
https://rally1.rallydev.com/analytics/1.27/<YourSubscriptionOID/artifact/snapshot/query.js?find={_Type:"Defect",_ItemHierarchy:<OIDofStory>,__At:"current"}&fields=["ObjectID"]
If all you really want is the count, then add:
&pagesize=1
and pluck the TotalResultCount out of the top part of the result.