condition data items corresponding to the maximum m retrieval objective columns cs 1 cs 2 and cs m associated with the resident key registers k 1 k 2 k m are sequentially stored in the resident key registers k 1 k 2 k m and that the retrieval condition data corresponding to the retrieval objective columns cs m 1 cs s exceeding step 8 the capacity of the resident key registers of which the number is represented as m is assigned to the non resident key register k t by assuming the key register number k to be 34 t 34 thereby continuing the collating operation while sequentially updating the preceding retrieval condition data steps 9 13 further the comparison results from the comparator 8 for each record with respect to the retrieval objective columns cs 1 cs 2 and cs s are evaluated in a cumulative fashion by the controller 110 for each record stored in the register 12 when a predetermined condition is statisfied a signal denoting a condition that a record matching with the predetermined retrieval condition is found and records satisfying the retrieval condition are delivered to the general purpose computer 3 steps 14 15 moreover in the retrieval operations for the second and subsequent records r 2 r 3 since the retrieval condition data corresponding to the retrieval objective columns cs 1 cs 2 and cs m have already been inputted to the resident key registers k 1 k 2 k m as shown in fig4 b and 5b the operation to read out the retrieval condition data from.