Data compression method data retrieval method data retrieval apparatus recording method and data packet signal

摘要

PURPOSE: A data retrieval apparatus is provided to efficiently retrieve from plural data packets containing main data and retrieval data compressed for efficient retrieval of the main data, the main data on the basis of an inputted search key. CONSTITUTION: A Central Processing Unit(CPU)(51) includes an Micro Processing Unit(MPU) executes a control program stored in a ROM (Read-Only Memory)(52) to control the database retrieval apparatus in its entirety on the basis of signals inputted from a key operation block(54) and, at the same time, executes processing for retrieving main data that corresponds to an inputted character string. The ROM(52), constituted by a mask ROM, an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), or a flash memory for example, stores the control program to be executed by the CPU(51), basically fixed parameters necessary for the execution of the control program, and font data.