GROUP-BY PROCESSING SYSTEM

摘要

PROBLEM TO BE SOLVED: To speed up access processing to a storage device by sequentially outputting plural records outputted correspondingly to hash function values to a secondary storage device such as a disk as one block. SOLUTION: A record group in a list 11 to be hashed stored in the secondary storage device is hashed by a processor 12 and the hashed result is outputted to the secondary storage device again as a hashed list 21 and an auxiliary information list 22. Namely records in the list 11 are temporarily stored in an input buffer 13 and a pointer from the butter 13 to a storing position in a record buffer 14 is stored in a hash table 15 correspondingly to hash function values calculated from the values of keys for the records. Then plural records stored in the table 15 are collected as one block and outputted as the hashed list 21 and the auxiliary information list 22 through a hashed list output buffer 18 and an auxiliary information list output buffer 19.