exception conditions which may have occurred during the execution of an activator eg abnormal table end and provides output data status information for example number of rows processed and any per table data eg row counts the operation of the exemplary relational database co processor rdcp 40 will now be described in detail at any given time the rdcp 40 may be dormant or active for each transaction ie each 34 packet 34 of work passed from the host processor the rdcp enters an active state passing through three modes of operation activation execution and termination with reference to fig1 there is shown an exemplary format of an activator program 150 a header portion 152 contains addresses of the next activator and input output areas and is loaded into the interface and stream control unit 42 fig3 a classifier portion 154 defines the nature of the transaction and the lengths of the four parts of the activator which follow this is loaded into the database engine control unit 140 a field descriptions portion 156 lists the type size specifications for relevant fields and gaps and is loaded into the relevant field selection unit 70 as per row layout a relational primitives portion 158 lists the compare type instructions used to load the comparand identification unit 80 and compare cells 90 a logic primitives portion 160 lists the logic connectives with their input selection masks and is loaded into logic processing unit 100 and a output selection portion 162 includes the qualification mask code plus between one and four output selection codes to be loaded into the corresponding register and store in the output selection unit 110 in operation a dormant rdcp.