Introduction Netezza is a data warehousing appliance that uses an Asymmetric Massive Parallel Processing Architecture.  The Netezza architecture is driven by two fundamental principles- process close to the data source and do not move data unless absolutely necessary. Among the two principles, the latter is implemented primarily by commodity hardware Field Programmable Gate Arrays (FPGAs).  FPGA plays the pivotal role in filtering out data as soon as possible, removing I/O bottlenecks, freeing up valuable downstream components such as memory and processor. Zone Maps are internal data structures of Netezza that enables FPGAs to filter out data. In simplistic terms, a