Exercise 12.4 Consider the following schema with the Sailors relation:Sailors(sid: integer...

Exercise 12.4 Consider the following schema with the Sailors relation:

Sailors(sid: integer, sname: string, rating: integer, age: real)

For each of the following indexes, list whether the index matches the given selection conditions. If there is a match, list the primary conjuncts.

1. A B+-tree index on the search key 〈 Sailors.sid 〉.
   1. σ_{Sailors.sid<50,000}(Sailors)
   2. σ_{Sailors.sid=50,000}(Sailars)
2. A hash index on the search key 〈 Sailors.sid 〉.
   1. σ_{Sailors.sid<50,000}(Sailors)
   2. σ_{Sailors.sid=50,000}(Sailars)
3. A B+-tree index on the search key 〈 Sailors.sid, Sailors.age 〉.
   1. σ_{Sailors.sid<50,000∧Sailors.age=21} (Sailors)
   2. σ_{Sailors.sid=50,000∧Sailors.age>21} (Sailors)
   3. σ_{Sailors.sid=50,000}(Sailors)
   4. σ_{Sailors.age=2l}(Sailors)
4. A hash-tree index on the search key 〈 Sailors.sid, Sailors.age 〉.
   1. σ_{Sailors.sid=50,000∧Sailors.age=21} (Sailors)
   2. σ_{Sailors.sid=50,000∧Sailors.age>21} (Sailors)
   3. σ_{Sailors.sid=50,000}(Sailors)
   4. σ_{Sailors.age=21}(Sailors)