A computer-implemented method for executing a query on data items located at different places in a stream of near real-time data to provide near-real time intermediate results for the query, as the query is being executed, the method including: from time to time, executing, by one or more computer systems, the query on two or more of the data items located at different places in the stream, with the two or more data items being accessed in near real-time with respect to each of the two or more data items; generating information indicative of results of executing the query; and as the query continues being executed, generating intermediate results of query execution by aggregating the results with prior results of executing the query on data items that previously appeared in the stream of near real-time data; and transmitting to one or more client devices the intermediate results of query execution, prior to completion of execution of the query.