Comment Comment by deepsun Checked just the first two answers:1. MoM Percent ChangeIt's better to use windowing functions, I believe it should be faster than self-join.2. It seems that the first solution is wrong -- it returns whether "a"-s parent is Root/Inner/Leaf, not "a" itself.I'd instead add a "has_children" column to the table, and then it would be clear.Second solution works, but without optimization it's 1 query per row due to nested query -- slow, but not mentioned. parent deepsun 6 years ago
1. MoM Percent Change
It's better to use windowing functions, I believe it should be faster than self-join.
2. It seems that the first solution is wrong -- it returns whether "a"-s parent is Root/Inner/Leaf, not "a" itself.
I'd instead add a "has_children" column to the table, and then it would be clear.
Second solution works, but without optimization it's 1 query per row due to nested query -- slow, but not mentioned.