MDEV-16934introduced eq_range_index_dives_limit into 10.2.8 and 10.3.0.
The default was set to 0 (which means no limit) in order to not introduce
optimizer behavior changes into stable versions.
The question is: should 10.4 also have 0 by default or we can set it to some
finite limit? MySQL's default value is 10.
After the decision was: It should be set to 10. This is what this task is about.
Saw MYSQL 8.0 , the default there is 200
Sergei Petrunia Igor Babaev for your information