1. A method comprising: receiving a query statement requiring at least one calculated attribute; generating a data flow graph comprising a plurality of nodes for executing the query, at least one of the nodes corresponding to the at least one calculated attribute and having at least one level of child nodes, the generating comprising: generating, for each of the nodes corresponding to the at least one calculated attribute, at least one filter; and pushing the generated filters down to a corresponding child node; initiating executing of the query using the generated data flow graph.