1. A computer program product for initializing a streaming application for execution on one or more compute nodes, each compute node adapted to execute one or more stream operators, the initialization including compiling code on a compiler system hosted by the computing device, the computer program product comprising a non-transitory computer readable storage medium having program code stored thereon, the program code, when executed on a computing device, causes the computing device to: examine, with a compiler system, an operator graph with a plurality of stream operators having a first stream operator written in a first set of programming instructions that outputs a plurality of tuples to a second stream operator; determine, with the compiler system, an existence of a defined processing condition at the second stream operator of the plurality of stream operators during compile-time, the defined processing condition includes a tumbling windowing condition that arranges a subset of tuples to be processed by the second stream operator from an input of the plurality of tuples by storing incoming tuples until a window is full, and flushes the stored tuples from the window; and modify the first stream operator, with the compiler system during compile-time, by compiling code that results in adding a grouping condition into the first stream operator of the plurality of stream operators in response to the determining of the existence of the defined processing condition at the second stream operator, wherein the grouping condition causes the first stream operator to output a specific group of tuples from the plurality of tuples to the second stream operator, wherein adding a grouping condition causes the first stream operator to have a second set of programming instructions different than the first set of programming instructions.