1. A computer implemented method to execute a runtime callback function, comprising: transforming multidimensional analytical metadata associated with an application server into an in-memory executable metadata, to generate an instance of an in-memory executable calculation scenario; analyzing the instance of the in-memory executable calculation scenario to determine one or more process callbacks associated with a plurality of nodes of the in-memory executable calculation scenario; and based upon the determined one or more process callbacks, a processor of a computer executing the runtime callback function by executing a selection callback at the plurality of nodes of the in-memory executable calculation scenario, including: deriving a filter condition associated with the application server and executing the selection callback at a system runtime to generate a resultant; and transforming the resultant into an in-memory executable runtime callback function, and executing a transformation callback at one or more part providers associated with the in-memory executable calculation scenario, including: based upon an executed query, determining an associated calculation pattern, and determining a part provider associated with the calculation pattern to retrieve one or more associated subsets for processing.