8. A non-transitory 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 input data stream related to an application; instructions that cause the one or more processors to generate an input relation from the continuous input data stream; instructions that cause the one or more processors to store the input relation as an external data source in a database of historical data; instructions that cause the one or more processors to receive a continuous query that identifies the input relation and a range value window operator associated with the input relation; instructions that cause the one or more processors to execute the continuous query to generate an output relation, the continuous query executed by applying the range value window operator on an attribute of the input relation to generate the output relation, the attribute comprising a characteristic of an event associated with the input relation; instructions that cause the one or more processors to determine whether the event associated with the input relation occurs within a specified time range defined by the range value window operator; instructions that cause the one or more processors to determine inserting or removing the event with respect to the output relation based at least in part on the determination of whether the event associated with the input relation occurs within the specified time range; and instructions that cause the one or more processors to provide data records of the output relation, the output relation comprising at least the event when the event was inserted based at least in part on being within the specified range defined by the range value window operator.
8. A non-transitory 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 input data stream related to an application; instructions that cause the one or more processors to generate an input relation from the continuous input data stream; instructions that cause the one or more processors to store the input relation as an external data source in a database of historical data; instructions that cause the one or more processors to receive a continuous query that identifies the input relation and a range value window operator associated with the input relation; instructions that cause the one or more processors to execute the continuous query to generate an output relation, the continuous query executed by applying the range value window operator on an attribute of the input relation to generate the output relation, the attribute comprising a characteristic of an event associated with the input relation; instructions that cause the one or more processors to determine whether the event associated with the input relation occurs within a specified time range defined by the range value window operator; instructions that cause the one or more processors to determine inserting or removing the event with respect to the output relation based at least in part on the determination of whether the event associated with the input relation occurs within the specified time range; and instructions that cause the one or more processors to provide data records of the output relation, the output relation comprising at least the event when the event was inserted based at least in part on being within the specified range defined by the range value window operator. 10. The computer-readable memory of claim 8 , wherein the input relation is an external data source generated based at least in part on one or more archived relations related to the application.