Integrated circuits and methods relating to hardware acceleration include independent, programmable, and parallel processing units (PU) custom-adapted to process a data stream and aggregate the results to respond to a query. In an illustrative example, a data stream from a database may be divided into data blocks and allocated to a corresponding PU. Each data block may be processed by one of the PUs to generate results according to a predetermined instruction set. A concatenate unit may merge and concatenate a result of each data block together to generate an output result for the query. In some embodiments, very large database SQL queries, for example, may be accelerated by hardware PU/concatenate engines implemented in fixed ASIC or reconfigurable FPGA hardware circuitry.