Hello,

I have a table with a field that has about 20% not null values and 80%
null and I want to select the not null values with a help of an index.
However, if I

SELECT my_field FROM my_table WHERE my_field IS NOT NULL

the optimizer use natural, no matter that I set the index ascending or
descending. I think that it should normally use it, given that there are
far less values for not null.

SELECT my_field FROM my_table WHERE my_field IS NULL
use that index.

Is this a normal behavior?

TIA

Radu