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Exercise 7: Query with R-trees

Using the following R-tree:

[Diagram:Pics/select/r-treeA.png]

Show how the following queries would be answered: 

Q1: select * from Rel where X='a' and Y=4
Q2: select * from Rel where X='i' and Y=6
Q3: select * from Rel where 'c'≤X≤'j' and Y=5
Q4: select * from Rel where X='c'

Note: can view unknown value X=? as range min(X) ≤ X ≤ max(X)