This topic describes how to set up a regular schedule for deleting historical tag data.
Currently Location Awareness Services for WebSphere® Sensor Events does not automatically archive historical data. Therefore, it is necessary to delete historical data on a regular basis to increase performance. You can schedule tag data to be deleted on a regular basis using the ATLASDB_DEL_TAG_HISTORY_SCHEDULE.bat script. The script schedules a task to delete all historical data entries that are older than eight hours and for which newer data is available. This allows you to consistently delete historical data.
Make sure you plan carefully for the deletion of historical tags and events. For example, if you have a lot of events in the CEI database within a short period of time, this can lead to performance degradation. You should also use the Web service to delete and archive CEI events as the notification program for the automatic clean up of those events, since they do not need to be kept.
To retain historical data for a longer period of time, you must archive and back up your data separately.
Complete the following steps to set up a regular deletion process for historical data: