frequency histogram下 effective index selectivity的计算

Yong Huang

So you think Oracle changes its calculation formula when it knows the frequency of each value. That's what I thought. I'm just not happy with this conclusion. I thought there might be a better explanation.

Yong Huang

sprite731

:-)   ,  "Oracle changes its calculation formula when it knows the frequency of each value"   is just my guess,  because so far I've not found any official papers to prove this point since I started  searching on Google, and only this "guess" can make sense.
If you or anyone else could find something formal to better explain why , pls share with me.
Thanks for your patience, Yong Huang.