1. A method comprising: receiving, by a database server from a remote application server, a query associated with a calculation scenario that defines a data flow model that includes a plurality of calculation nodes, each calculation node defining one or more operations to execute on the database server, at least one of the nodes being a semantic node specifying an operation requiring special handling; modifying, by the database server, the query using the semantic node; modifying, by the database server, the calculation scenario based on the modified query; instantiating, by the database server, the modified calculation scenario; executing, by the database server, the operations defined by the calculation nodes of the modified calculation scenario to result in at least one result set; and providing, by the database server to the application server, the at least one result set.