An automatic telephone directory inquiry service system

A real-time, on-line information storage and retrieval system for telephone information service has been designed. The input and output of the system are processed in Chinese via a keyboard and a graphic display unit respectivey. Functions of the system include: sorting, merging, updating, displaying, and printing of data. In order to avoid a serial, exhaustive search, the file is subdivided into blocks of length x. The optimal size of each block is determined so that the average number of comparisons (file accesses) to locate a record is minimized versus some combined search methods. The system has been tested on a telephone office of medium capacity, roughly 8000 subscribers. The number of daily queries is about 1600 and the updating rate is approximately 50. By comparison of the slowest system's response time (0.24 sec.) with the quickest manual response time, the system is, at least , 130 times faster.