Initiating discussion for adding a feature to calculate storage size. *Feature: *Storage Size Datasource Function *Details:* The storage size datasource function provides the ability to calculate a collection or an index size by calling the datasource function and providing the proper arguments for the desired function.
*APE*: https://cwiki.apache.org/confluence/display/ASTERIXDB/APE+12%3A+Storage+Size+Datasource+Function -- Regards, Hussain Towaileb
