Methods and apparatus, including computer program products, are provided for union node pruning. In one aspect, there is provided a method, which may include receiving, by a calculation engine, a query; processing a calculation scenario including a union node; accessing a pruning table associated with the union node, wherein the pruning table includes semantic information describing the first input from the first data source node and the second input from the second data source node; determining whether the first data source node and the second data source node can be pruned by at least comparing the semantic information to at least one filter of the query; and pruning, based on a result of the determining, at least one the first data source node or the second data source node. Related apparatus, systems, methods, and articles are also described.