| 摘要 |
<p>PURPOSE:To enable the limitation of recording by preferentially reducing the recording amount at the time of a data restoration by not recording such data that can be regarded as equal to each other in the case of referring the log data. CONSTITUTION:When the data are supplied from a data generating source 1 in a data absence state and at a unit time, a log comparing part 31 assorts the data with an assorting key 42 and records an index, the recording record and the time to the log data 41 to be set in a log recording state. If new data is generated under such condition, the log comparing part 31 decides the presence or absence of the same assorting key and the differential data. If the presence of the same assorting key and the differential data 43 are confirmed, the part 31 decides whether the collected data reached its upper limit value. If the collected data are less than the upper limit value, the data 43 is recorded. Meanwhile, the final differential data is recorded in an idle area based on the next entry as long as the entry is confirmed for the differential data and the data 43 already exists. When the differential data reaches it upper limit of collection, only the disuse number of a disuse counter 44 is updated and the differential data is not recorded.</p> |
