| 摘要 |
PURPOSE:To shorten the retrieval time by automatically generating a digest of messages at the time of stay of messages whose number exceeds a preliminarily set prescribed value. CONSTITUTION:A retrieval monitor part 310 which monitors time intervals of retrieval and a digest generating part 330 are provided, and this digest generating part 330 generates the digest of messages when the number of messages in a storage part 140 exceeds the prescribed value and retrieval is not performed during storage of these messages. The generated digest is stored in the storage part 140, and the digest is read out from the storage part 140 and is presented to a user when the user indicates retrieval. Since the digest consists of only, for example, header information of messages, retrieval does not take a long time though a large number of messages stay in the storage part because a long time elapses after the preceding retrieval. Thus, the retrieval time is shortened. |
