Embodiments of the present invention provide processing elements that are capable of performing high level database operations in hardware based on machine code instructions. These processing elements employ a dataflow architecture that operates on data in hardware without interruption or software. A scanning/indexing processing element may comprise logic that analyze database column groups stored in local memory, perform parallel field extraction and comparison, and generates a list of row pointers (row ids or RIDs) referencing those rows whose value(s) satisfy an applied predicate. The scanning/indexing processing may also be used to project database column groups, search and join index structures, and manipulate in-flight metadata flows, composing, merging, reducing, and modifying multi-dimensional lists of intermediate and final results. Furthermore, a scanning/indexing processing element may be used for joins with indexes, like a Group Index, which involves the association of each input tuple with potentially many related data components, in a one-to-many mapping. An XCAM processing element may comprise logic to perform associative database operations, like accumulation and aggregation, sieving, sorting and associative joins.