Join Optimizer: histogram statistics/ needed for cost-based optimization

The previous step delivers a statistics that allows to detect uniqueness of a column to be able to cut lops in a JOIN graph the most effective way.
The current step will deliver a histogram collected for columns of tables. The strained goal is to collect a Number of Dictinct Values statistics also.
In the scope of this project the mentioned statistics collection is a manual operation and run by ANALYZE TABLE command as previously.