Two levels (lvl1 and lvl2) are available for collecting optimizing information, and the contents that can be collected vary depending on the level. Each level is referred to as an optimizing information collection level. These levels have the following characteristics:

lvl1: The collection time is short, but accuracy of optimization is not very high.

lvl2: Accuracy of optimization is high, but the collection time is long.

For details about these optimizing information collection levels, see Optimizing information collection levels in the manual HiRDB Version 9 Command Reference.