Adaptive Server 15.0.2 ESD #2 introduces a change to the 'histogram tuning factor' parameter in sp_configure. This parameter controls the number of steps Adaptive Server analyzes per histogram for update statistics, update index statistics, update all statistics, and create index.
If you set the 'histogram tuning factor' configuration parameter to its default value of 20 and a large number of steps are requested for the histogram, then the actual step count used for the histogram is limited to:
min (max (400, requested_steps), histogram_tuning_factor * requested_steps)
This is designed to reduce the procedure cache usage.
