MULTI-THREAD SORT PROCESSING SYSTEM AND METHOD USING WORK FILE

PROBLEM TO BE SOLVED: To speed up a sort processing by making an external sorting processing to be executed on a general purpose information processor provided with plural CPUs into multiple thread and making comparison and I/O into parallel processing. SOLUTION: This system is provided with a block area 411 for blocking plural strings inside a work file 3 by an equal number and reading and sorting the strings corresponding to blocks, a means 6 for allocating a buffer 412 for block merging in a double buffer structure for holding an intra-block sorted result, an input means 8, an intra-block sorting processing means 7, a block merging means 9 for merging sorted results for the respective blocks, a record output means 5 and a main processing means 1 for calling the means 6, 9 and 5 and controlling the entire sorting. The main processing means 1 generates and activates input processing and intra-block sorting processing threads for the respective blocks, assigns a main thread composed of a main processing and a subordinate processing and the threads for the generated plural blocks to the plural CPUs and parallel processes them.