1 ) A computer apparatus for searching an in-memory database comprising: a plurality of compute nodes coupled for data communications through a global combining network, each of the plurality of compute nodes having a processor and computer memory operatively coupled to the processor, the computer memory having disposed within it a portion of the in-memory database, and a search mechanism in the computer memory that receives a unique search key and searches the portion of the in-memory database using the search key, if a match for the key is found, the search mechanism stores a corresponding data record in a combining network buffer and if a match is not found the search mechanism stores zeros in the combining network buffer; and the search mechanism contributes to a network all reduce operation on the combining network buffers by combining data received from a child node with the contents of the combining buffer to form a result and passing the result to a parent node.