12. A computer-readable memory storing a plurality of instructions executable by one or more processors, the plurality of instructions comprising: instructions that cause the one or more processors to receive a continuous query configured to process data objects, the continuous query including at least one of an identifier of the data stream or an identifier of historical data; instructions that cause the one or more processors to generate a query graph based at least in part on the continuous query; instructions that cause the one or more processors to receive a window size from an entity associated with the data stream; instructions that cause the one or more processors to generate a data object to include at least a portion of the historical data and that is configured to receive incoming events of the data steam that are within a window that corresponds to the window size; instructions that cause the one or more processors to initialize the continuous query with the data object to process at least the portion of the historical data based at least in part on the window size; and instructions that cause the one or more processors to evaluate the data object using the continuous query based at least in part on the historical data.
14. The computer-readable memory of claim 12 , wherein the plurality of instructions further comprise instructions that cause the one or more processors to determine an amount of historical data with which to initialize the continuous query based at least in part on the window size.